Drive unit for a vehicle that can be driven by human muscle force and by an electric motor

Abstract

The invention relates to a drive unit (1) for a vehicle (F) which can be driven by drive energy provided by human muscle power and by electric motors, which drive unit is constructed particularly narrow and comprises two shaft transmissions (13, 18) and two electric motors (22, 27), wherein the drive energy provided by human muscle power and by electric motors (22, 27) can be transmitted together onto an output driven shaft (12).

Description

Technical Field

[0001] The present invention relates to a drive unit for a vehicle that can be driven simultaneously by human muscle force and drive energy provided by an electric motor. Background Technology

[0002] The types of vehicles referred to are single-track or multi-track vehicles, such as bicycles, especially e-bikes, electric bicycles, or electric-assisted bicycles (Pedelec), but also include water bikes, pedal boats, or wheelchairs. These types of vehicles are particularly defined under vehicle categories L1e, L2e, L3e, L4e, L5e, L6e, and L7e according to Article 4 of EU Regulation 2013 / 168 / EU, which came into effect on 15 January 2013. Furthermore, vehicles of this type also include: especially vehicles with a maximum speed of 6 km / h due to their structural design; vehicles specifically designed for use by people with disabilities, such as wheelchairs; vehicles specifically designed for use in sports competitions; bicycles with pedal-assist devices equipped with an electric motor-driven auxiliary drive with a maximum nominal continuous power of 250 W, wherein the assistance is interrupted when the rider stops pedaling, and the assistance gradually decreases as the vehicle speed increases, and is interrupted before the speed reaches 25 km / h; self-balancing vehicles with electric motor-driven travel drives; sports vehicles with pedal drives; vehicles with pedal drives and having at least one seat; and vehicles with pedal drives having an R-point of ≤400 mm (according to ECE-R 17). These vehicles typically have one front wheel and at least one rear wheel, which are interconnected by a frame. Of course, multiple rear wheels, such as two rear wheels, and / or multiple front wheels, such as two front wheels, may also be present, and the front and rear wheels may be present in any combination. These wheels can be arranged side-by-side, for example, transversely to the direction of travel, as in wheelchairs, tricycles, or sidecars, or sequentially, one in front of the other, as in two-seater bicycles. Increasingly, such vehicles are equipped with at least one motor that provides assistance to the user while propelling the vehicle. Often, the vehicle is not solely driven by the motor, but rather the motor assists the user while the vehicle is propelled by their own muscular strength. In this case, the degree of assistance is usually selectable. In this way, the user can precisely apply their power to the extent they are able or desire while using the vehicle, while still maintaining a comfortable and everyday-usable speed.

[0003] Besides providing assistance to the user when driving a vehicle, it is also known that the drive unit for such a vehicle is equipped with two motors and an accumulator transmission. In this way, a continuously variable transmission (CVT) can be implemented, which is controlled, for example, by a control unit. In this case, the operator does not need to find the appropriate gear from multiple available discrete gears, as is done, for example, in a conventional bicycle. Instead, the appropriate gear ratio for the current driving conditions is set by the control unit via stepless operation of at least one of the motors on the accumulator transmission. Such a drive unit is known, for example, by EP 1 642 820 A1 and EP 2 218 635 A1. In the aforementioned documents, a planetary transmission is used as the accumulator transmission.

[0004] The problem with current drive units lies in their structural dimensions, particularly their transverse dimensions to the vehicle's longitudinal axis. These drive units are typically located on or near the wheel hub, or on or near the drive bearing, such as the bottom bracket bearing. On the one hand, the drive unit should not protrude excessively from the wheels on either side. On the other hand, when located on the bottom bracket bearing, it is important to note that, for example, due to human anatomy, the crank arms of the pedals should generally maintain a maximum axial spacing of 140-180 mm. Since the drive unit is also located between the crank arms, it is obvious that the drive unit should be designed to be as narrow as possible to provide a comfortable riding experience even on long distances. However, this also introduces a series of structural problems, as the necessary rotating bearings and flywheels within the drive unit each impose specific space requirements. Especially in the direction of rotation of the bottom bracket bearing or rear wheel, the combined drivetrain and motor typically occupy a significant amount of structural space within the drive unit, which undesirably increases the overall width of the drive unit. Summary of the Invention

[0005] Therefore, the object of the present invention is to provide a drive unit that is configured as narrow as possible, particularly transversely to the direction of travel of the vehicle. Simultaneously, the drive unit should be flexibly controllable and capable of covering the full functional range of current drive units.

[0006] The solution is achieved through a drive unit according to the invention for a vehicle capable of being driven simultaneously by both human muscle force and electric motor power. Furthermore, the invention also relates to a vehicle having such a drive unit.

[0007] The drive unit according to the invention includes an input drive shaft for transmitting drive energy generated or provided by human muscle force. That is, the input drive shaft can be, for example, a bicycle crank or a crank that is non-rotatably connected to it. Alternatively, the input drive shaft can also be rotatably fixed to a traction gear, such as a sprocket. Thus, the input drive shaft is configured such that it can be rotated by the operator or rider of the vehicle using human muscle force, for example, by pedaling on a bicycle. This can be done directly or indirectly. In particular, it is configured such that this occurs before the motor in the direction of force transmission flow originating from the point where human muscle force enters the entire transmission system.

[0008] Furthermore, the drive unit according to the invention includes an output driven shaft for outputting drive energy to a traveling device. The traveling device is, for example, at least one wheel (or, for a water vehicle, a propeller), which is rotated by the drive energy transmitted by the output driven shaft, thereby propelling the vehicle. The output driven shaft may be non-rotatably connected to a traction gear, such as a sprocket. Alternatively, the output driven shaft may also be configured to be non-rotatably connected to a hub housing, which transmits rotational motion to the traveling device, for example, via spokes. Since the output driven shaft transmits its rotation to the traveling device of the vehicle, the drive unit is thus configured to apply rotation to the output driven shaft corresponding to the desired travel speed of the vehicle. Thus, along the direction of force transmission from the point of entry of human muscle force, the output driven shaft is functionally positioned between the input drive shaft and the traveling device driven by the drive unit.

[0009] Accordingly, the drive unit is configured such that driving energy is transmitted from the input drive shaft to the output driven shaft. However, it is also configured such that the drive unit can adapt the rotational speed and torque transmitted to the output driven shaft to the requirements of the current operating conditions. For this purpose, the drive unit includes a drive shaft transmission device arranged around a rotating shaft, the drive shaft transmission device having a first shaft-driven generator, a first flexible gear, and a gear ring. The rotating shaft can be, for example, the central shaft of a central bearing or the axle of a traveling device, especially the axle of a traveling device driven by the drive unit. The shaft transmission device is a transmission device that is particularly suitable for current applications due to its simple and compact construction, robustness, and high reduction ratio. Shaft transmission devices are themselves described in the prior art and are known to those skilled in the art, for example, by DE 1 135 259 B. Such a shaft transmission device can, for example, convert the high speed with low torque of the shaft-driven generator to the low speed with high torque of the flexible gear and / or gear ring, and vice versa. Furthermore, the drive unit includes a drive motor with a stator and rotor arranged around a rotation axis. The drive energy of the drive motor can be transmitted to the output driven shaft via a drive shaft transmission. Therefore, the drive motor can be used to assist the driver or provide assistance using their muscular strength, in order to transmit the drive energy provided by the motor to the output driven shaft and thereby contribute to the forward movement of the vehicle. Through the high reduction ratio of the shaft transmission, the high speed and low torque of the motor can be converted into a low speed with high torque, which can be used to drive the vehicle. For this purpose, the drive motor is preferably operatively connected to the shaft-driven generator of the drive shaft transmission. In other words, the rotor of the drive motor is preferably non-rotatably connected to the shaft-driven generator or even integrally formed with the shaft-driven generator. The output end of the drive shaft transmission is preferably formed by a gear ring in the present case. This gear ring is particularly non-rotatably connected to the output driven shaft of the drive unit.

[0010] The drive unit according to the invention additionally includes a variable shaft transmission device disposed in the transmission system between the input drive shaft and the output driven shaft, the variable shaft transmission device having a second shaft-driven generator, a second flexible gear, and a gear ring. Thus, the drive unit according to the invention simultaneously includes two shaft transmission devices, but these two shaft transmission devices can perform different functions, as detailed below. Specifically, the variable shaft transmission device is configured such that it receives driving energy from human muscle force from the input drive shaft and transmits it to the output driven shaft of the drive unit. For example, for this purpose, the input drive shaft is non-rotatably connected (e.g., via a flywheel, which will be described in detail later) to a slowly rotating transmission component of the variable shaft transmission device, such as a flexible gear or gear ring. Preferably, the input drive shaft is non-rotatably connected to the flexible gear, and thus the driving energy from human muscle force is introduced or introduced into the variable shaft transmission device via the flexible gear. In this preferred embodiment, the gear ring is non-rotatably connected to the output driven shaft, so that the driving energy from human muscle force is transmitted to the gear ring via the flexible gear and thereby drives the output driven shaft. Since the flexible gear is permanently engaged with the gear ring via its teeth, the rotational speed of the input drive shaft can initially be transmitted one-to-one to the output driven shaft. However, the transmission ratio between the input speed via the flexible gear and the output speed via the gear ring can be influenced, for example, by means of a separately present shaft-driven generator. According to the invention, for this purpose, a variable motor having a stator and a rotor is provided, particularly arranged around the rotating shaft, and the driving energy of the variable motor is also introduced into the variable shaft transmission. Furthermore, this arrangement allows the accumulated energy from human muscle force and the variable motor to be transmitted to the output driven shaft via the variable shaft transmission. This includes both adding additional energy to the energy introduced into the output driven shaft by human muscle force and the variable motor offsetting the energy introduced by human muscle force, thereby deducting the driving energy for the output driven shaft. The variable motor is operatively connected to the shaft-driven generator, particularly the variable shaft transmission. For example, the rotor of the variable motor is configured to be non-rotatable relative to the shaft-driven generator. Therefore, the driving energy provided by the variable motor is also transmitted to the gear ring of the variable shaft transmission, and particularly to the output driven shaft, via the shaft-driven generator. The variable shaft drive converts the speed ratio between the input drive shaft and the output driven shaft, and / or adds the driving energy from human muscle force to the driving energy from the variable motor. The variable shaft drive and / or variable motor are preferably arranged around the rotational axis, thereby achieving a compact structural form while maintaining a favorable force transmission flow.

[0011] In the drive unit according to the invention, the gear rings of the drive shaft transmission and the variable shaft transmission are configured to be non-rotatable relative to each other. This can be achieved by connecting the two gear rings to each other in a non-rotatable manner using a connecting element, such as a fixing pin or the like. However, it is also possible, and in the present case preferred, that the two gear rings are configured as an integral unit. Thus, in this embodiment, a gear ring unit is provided having two internal teeth spaced apart in the axial direction of the rotating shaft, one internal tooth for engaging a first flexible gear and the other for engaging a second flexible gear. Here, the two internal teeth may be spaced apart in the axial direction, or they may transition directly to each other in the axial direction. This non-rotatable configuration of the two gear rings allows the accumulated drive energy from human muscle force, the drive motor, and the variable motor to be transmitted to the output driven shaft at this location. Thus, this gear ring unit constitutes the accumulation point of the two shaft transmissions of the drive unit to the output driven shaft. Both gear rings, in particular, have internal teeth configured to complement the external teeth of the corresponding flexible gears (the internal teeth of the gear rings have a higher number of teeth than the external teeth of the flexible gears, which is common in shaft drives). Therefore, the two shaft drives of the drive unit are interconnected via this common gear ring. Specifically, the two shaft drives use the common gear ring as either the driven end or the output end of the drive unit, thereby loading the gear ring and thus the output driven shaft with the accumulated driving energy or power of the two motors and the driver's muscles. That is, according to the first core concept, the invention uses two shaft drives to transmit the accumulated driving energy or power of the two motors and the driver of the vehicle to the gear rings in interaction or to the common gear ring, and from there to the output driven shaft. This allows the drive unit to have a particularly elongated structure. As previously described, and particularly in the previously mentioned configuration of the motor, using a common gear ring or two gear rings of two transmissions configured to be non-rotatable relative to each other as an accumulation point and / or transmission output or driven end in principle contributes to axial space savings in any drive with two transmissions, regardless of the type of transmission used, as long as that type of transmission can output power through the gear ring. Therefore, this aspect also constitutes a separate invention, independent of the structural and functional features of the embodiments described herein, and can be claimed separately, in addition to improvements to the design scheme specifically described herein.

[0012] The drive motor and / or variable motor is preferably a synchronous motor, especially a three-phase synchronous motor, and more preferably a synchronous motor with an external rotor structure. In the embodiments described by the present invention, the synchronous motor is characterized by its particularly narrow size.

[0013] Depending on the rotation direction of the variable motor, the variable motor can vary the speed of the output driven shaft when the speed introduced by the driver through the input drive shaft is transmitted. This speed variation enables the output driven shaft to change its speed relative to the input drive shaft. For example, the output driven shaft can accelerate or decelerate relative to the input drive shaft, and the variable motor can maintain the set gear ratio for an extended period without further acceleration or deceleration. This is preferably used to create a continuously variable transmission between the input drive shaft and the output driven shaft, especially when used with the variable motor. By controlling the speed of the variable motor, the speed of the output driven shaft can be increased or decreased relative to the input drive shaft to any degree. Therefore, in conjunction with the control unit, which will be described in detail later, a comfortable pedal speed and pedal resistance can be set for the driver under any driving conditions, without being constrained by pre-defined gear levels.

[0014] According to a preferred embodiment of the invention, at least one of the flexible gears is configured as a sleeve extending along the rotation axis. Preferably, two flexible gears each constitute a sleeve extending along the rotation axis. Each sleeve is connected to a rotating bearing on one axial side, the rotating bearing rotatably supporting the sleeve, for example, relative to a fixed or stationary housing. On another axial side, each sleeve has an engagement area for a shaft-driven generator and, in particular, external teeth for a gear ring. Viewed along the rotation axis, a sleeve cavity exists between the rotating bearing and the shaft-driven generator. That is, the sleeve cavity describes a space, particularly radially, surrounded by the flexible gear and, in particular, the sleeve, from the rotation axis. The flexible gear, with its sleeve, being a bowl-shaped flexible gear, contributes to its bending and torsional characteristics, and thereby helps to achieve fault-free operation of the shaft drive. However, in the invention, the sleeve cavity is preferably used in a very efficient manner to save construction space. Therefore, it is particularly configured that at least one, preferably two, motors are at least partially, preferably completely, arranged in the sleeve cavity of the shaft drive corresponding to the respective motor in the axial direction of the rotation axis. In other words, for example, the drive motor is at least partially, preferably completely, housed within the sleeve cavity of the drive shaft transmission device in the axial direction of the rotating shaft, and / or the variable motor is at least partially, preferably completely, housed within the sleeve cavity of the variable shaft transmission device in the axial direction of the rotating shaft. That is, each motor is preferably at least partially and preferably completely surrounded by the corresponding sleeve of the flexible gear in the radial direction. The corresponding description of the motors particularly relates to the rotor and / or stator of the respective motor extending axially along the rotating shaft. Thus, according to a preferred embodiment, the drive motor and / or variable motor are surrounded by the sleeve of the flexible gear in the radial direction of the rotating shaft along their entire axial extension. In this way, the sleeve cavity is structurally designed to house at least one, preferably two, motors, thereby saving structural space. This is particularly efficient achieved by arranging the two flexible gear sleeves with their outer teeth facing each other in the axial direction of the rotating shaft.

[0015] Another preferred embodiment of the invention also relates to a space-saving arrangement of the motor. For this purpose, it is preferred that the drive shaft transmission device and / or variable shaft transmission device, including the shaft-driven generator, flexible gear, and gear ring, are arranged overlapping each other in a transmission plane perpendicular to the axis of rotation. That is, the shaft-driven generator, flexible gear, and gear ring of the respective shaft transmission device are arranged sequentially in the radial direction of the axis of rotation, particularly from the inside out in the aforementioned order and / or flush in the radial direction. Furthermore, the flexible gear, especially the sleeve of the flexible gear, is rotatably supported relative to a support in a bearing plane perpendicular to the axis of rotation. Within the scope of this application, a support refers, for example, to a fixed or stationary component of the drive unit and is configured, for example, to be fixed together with the housing or housing components. Now, it is preferred that the drive motor and / or variable motor are at least partially and preferably completely arranged between the transmission plane and the bearing plane. This also particularly relates to the rotor and / or stator of each motor extending axially along the axis of rotation.

[0016] In order to enable particularly precise control of the motor of the drive unit according to the invention, especially by the control unit described in detail below, it is preferable to provide at least one, particularly non-contact, speed and / or angle sensor, especially a Hall sensor, on the drive motor and / or on the variable motor. To save space as much as possible in accommodating the corresponding sensor within the drive unit, it is also alternatively provided that the at least one, particularly non-contact, speed and / or angle sensor is disposed, particularly within the sleeve cavity of the flexible gear. Therefore, the corresponding sensor is preferably also located between the transmission plane and the bearing plane.

[0017] Because the drive unit has multiple rotatable components and the rotatability of different components relative to a fixed housing, multiple rotary bearings, such as (grooved) ball bearings, are required to arrange these components, especially around a rotational axis, so that they can rotate relative to each other. This arrangement is preferably implemented such that these rotatable elements can all rotate around a common rotational axis, especially the central bearing axis or the rotational axis of the travel mechanism. A challenge in the specific implementation of this arrangement is that these rotary bearings, in order to fulfill their respective functions, must have extremely small widths; this width, especially the cumulative width of multiple rotary bearings along the axial direction, significantly contributes to the overall width of the drive unit. Therefore, the invention also aims to save structural space in the axial direction of the rotational axis by cleverly arranging the rotary bearings. Thus, for example, it is preferable to arrange the rotary bearing for the output driven shaft and the rotary bearing for the input drive shaft in a common shaft support plane perpendicular to the rotational axis. Consequently, these two rotary bearings are preferably arranged overlapping or stacked in the radial direction of the rotational axis. Particularly preferred is that these two rotary bearings are constructed as ball bearings having the same axial extension dimension along the rotational axis and completely overlapping in the radial direction of the rotational axis. In other words, the two rotary bearings are arranged side-by-side in the radial direction, rather than axially, thus saving the width of one of the rotary bearings along the axis of rotation. This arrangement of the rotary bearings for the output driven shaft and the input drive shaft is beneficial for saving axial structural space for virtually any drive, regardless of the type of transmission and motor configuration used. This is particularly relevant for applications in motor-assisted bicycles, such as electric bicycles or e-bikes. Therefore, apart from improvements to the design specifically described in this application, this aspect constitutes a separate and independent invention, independent of the structural and functional features of the embodiments described herein, and can be claimed separately.

[0018] To limit the axial width or extension of the drive unit, it is known to arrange multiple transmission devices or multiple motors side by side, for example, not along the axial direction, but in the radial direction about the axis of rotation. In other words, to limit the extension of the drive unit laterally to the direction of travel of the vehicle, compromises are made in the extension along the direction of travel or along the vertical direction. However, the object of the present invention is now to avoid such an increase in the drive unit along the direction of travel and / or along the vertical direction. Therefore, it is preferable to arrange the two motors and / or the two shaft transmission devices coaxially with each other about the axis of rotation. That is, the two motors and / or the two shaft transmission devices in particular have the same axis of rotation. Such an arrangement is not only particularly compact, but also has advantages in terms of the flow of force transmission through the drive system.

[0019] Since the two shaft drives share a common gear ring, at least functionally or structurally, it is particularly space-saving to arrange them close to each other. Therefore, it is preferable that the two shaft drives are configured adjacent to each other in the axial direction about the axis of rotation. In this case, the motors are preferably directly connected further outward in the axial direction. Further outward in the axial direction, a rotating bearing for the flexible gear relative to a fixed support is then arranged; this rotating bearing may, for example, include a flywheel. Therefore, it is generally preferable that the shaft drives, motors, and especially the rotating bearings of the flexible gears relative to the fixed supports, and especially the flywheel between the flexible gears and the stationary housing components, are symmetrically configured and arranged about a plane of symmetry extending perpendicular to the axis of rotation. Thus, the aforementioned components are preferably arranged mirror-symmetrically about the plane of symmetry along the axis of rotation. Furthermore, this has the advantage that components that are dual-use or structurally identical can be largely utilized for the variable shaft drive and the drive shaft drive, thereby advantageously maintaining a low component diversity in the drive unit.

[0020] As already explained, according to the invention, the gear ring of the shaft drive serves as either the output or driven end of the transmission. Therefore, driving energy from human muscle force can be introduced into the variable shaft drive via a shaft-driven generator or flexible gears. Preferably, the input drive shaft is non-rotatable to the flexible gears of the variable shaft drive in at least one rotational direction, and energy from human muscle force is introduced into the variable shaft drive via the flexible gears. For this purpose, the input drive shaft is preferably connected to the flexible gears of the variable transmission via a flywheel, which is locked or establishes a non-rotatable connection, particularly along the forward rotation direction or forward travel direction of the input drive shaft, thereby transmitting the corresponding rotational motion to the gear ring via the flywheel and the flexible gears. Furthermore, the flywheel also allows, for example, free backward pedaling, or allows the output driven shaft to rotate faster via two motors compared to the input drive shaft rotated by the driver.

[0021] Preferably, another flywheel is mounted on the flexible gear of the drive shaft transmission. The flexible gear of the drive shaft transmission is supported on a fixed housing component, particularly via a flywheel. The flywheel rotates freely, especially when the flexible gear rotates in the forward direction, and locks, especially when the flexible gear rotates in the opposite direction. If the vehicle moves forward, the output driven shaft and the common ring gear rotate forward. Consequently, the flexible gear of the drive shaft transmission also rotates forward. Since the flywheel rotates freely in this direction, the rotor of the drive motor does not need to be driven. Therefore, if driving is performed, for example, without motor assistance, by pure human muscle force, this can be done with low pedaling resistance. Conversely, if the drive motor is running to transmit auxiliary torque to the ring gear and thus to the output driven shaft, the flexible gear, supported on the fixed housing via the flywheel, transmits driving energy from the drive motor via a shaft-driven generator and the flexible gear to the ring gear and thus to the output driven shaft.

[0022] As already explained, the flywheel is preferably mounted on the flexible gear of the drive shaft transmission such that it rotates freely when the vehicle is moving forward and the drive motor applies little or no driving energy. In these conditions, it may be desirable for the drive motor to operate as a generator to recover kinetic energy. To achieve this, the flywheel is preferably configured to switch between a free-rotating position in one direction of rotation and a engaged or non-free-rotating position in that direction of rotation. In other words, the flywheel thus functions as a switchable clutch in that direction of rotation. Alternatively, a separate clutch unit can be provided, which can establish a non-rotatable connection between the flywheel and a fixed housing component, thereby bypassing the flywheel and achieving the same effect. In this way, the drive motor can operate as a generator, receiving driving energy from the gear ring and converting it into electrical energy. If the flywheel switches to its non-rotatable position, it means that the flywheel also establishes a non-rotatable connection between the flexible gear and the fixed housing component in the forward rotation direction. The flexible gear is thus locked and cannot rotate. In this way, driving energy is transferred from the gear ring to the shaft-driven generator and thus to the drive motor, which then acts as a generator and converts the driving energy into electrical energy, for example, to charge a storage device for electrical energy. In this way, the vehicle can also brake, especially when recovering electrical energy. This use of a switchable flywheel and / or a separate clutch unit to allow the drive motor to operate as a generator can, in principle, be achieved using any drive unit with a motor, regardless of the type of transmission used or the configuration of one or more motors. Therefore, apart from improvements to the design described herein, this aspect constitutes a separate, independent invention, independent of the structural and functional features of the embodiments described herein, and can be claimed separately.

[0023] The switchable flywheel is specifically used in flexible gears of drive shaft transmission devices, for example, in electric-assisted bicycles. By law, electric-assisted bicycles are only permitted to reach a maximum speed of, for example, 25 km / h (45 km / h for S-type electric-assisted bicycles) with motor assistance. Beyond this maximum speed, the motor power introduced by the drive unit must be zero. However, it is preferable that the rider can also exceed this speed limit using their muscle strength, thus requiring a faster transfer of rotation from the input drive shaft to the output driven shaft. In the drive unit according to the invention, this means that the variable motor, i.e., the motor of the variable shaft transmission device, responsible for adjusting the transmission ratio from the input drive shaft to the output drive shaft, must also transfer driving energy to the gear ring and thus to the output driven shaft via the variable shaft transmission device. To avoid violating legal regulations, it is now preferable to configure the drive motor to operate as a generator when the legally prescribed maximum speed is exceeded. At this point, the drive motor operates in such a way that it acts as a generator, drawing from the gear ring a drive energy or power corresponding to the drive energy or power applied to the gear ring by the variable motor and converting it into electrical energy. Alternatively, for example, if the variable motor has equal rotational speed and / or equal torque, the corresponding "negative" drive power of the drive motor can also be achieved by driving the drive motor in the opposite direction of rotation to the variable motor. Importantly, in this operating state, the cumulative drive energy or power of the two motors is generally zero, so the electric-assisted vehicle is driven solely by human muscle force and thus meets legal requirements. Therefore, it is generally preferred that the drive motor operates from the vehicle's maximum speed with a drive power opposite to and numerically equal to that of the variable motor, i.e., as a motor or generator, so that the total drive power applied by the motor to the output driven shaft is equal to zero. The corresponding control of the motor is performed by a control unit, which will be described in detail below. Furthermore, a suitable sensor system is provided to acquire relevant operating data important to the control unit, such as, for example, the current speed of the vehicle driven by the drive unit. Here, the drive unit is only responsible for achieving the desired transmission ratio between the input drive shaft and the output driven shaft, without providing auxiliary drive energy or drive power that acts in the vehicle's forward direction.

[0024] As previously described with respect to the rotary bearing, the flywheel also has a very small necessary axial extension dimension along the axis of rotation. Therefore, it is also advantageous that the flywheel is arranged radially overlapping with at least one rotary bearing relative to the axis of rotation, in order to reduce their overall common axial extension dimension. Thus, it is preferred that one rotary bearing is arranged overlapping the flywheel in a bearing plane perpendicular to the axis of rotation between the support and the flexible gear of the drive shaft transmission. Alternatively or supplementarily, a rotary bearing is arranged overlapping the flywheel in a bearing plane perpendicular to the axis of rotation between the support and the flexible gear of the variable shaft transmission. Particularly preferred is that the rotary bearing and the flywheel overlap each other by at least half, preferably at least two-thirds, and especially preferably completely with respect to their respective axial extension dimensions along the axis of rotation. The support is a fixed component, i.e., it does not rotate with the load, and is connected, for example, to other fixed housing components of the drive unit in a manner that prevents relative rotation.

[0025] This achieves further savings in the axial width of the drive unit, specifically by having a rotary bearing, preferably located together with the shaft drive in a plane perpendicular to the axis of rotation. That is, the rotary bearing overlaps with the shaft drive in the radial direction of the axis of rotation. The rotary bearing can be, for example, the rotary bearing of a motor rotor. Such a rotary bearing is necessary and therefore must be arranged to save space. Therefore, according to a preferred embodiment of the invention, the shaft-driven generator, flexible gear, and gear ring of the drive shaft drive and / or variable shaft drive are arranged together with the rotary bearing for the rotor of the drive motor and / or variable motor, especially relative to the support, in a plane perpendicular to the axis of rotation. That is, in this embodiment, the rotary bearing of the motor rotor moves into the shaft drive and, in particular, nests with the shaft drive. The corresponding rotary bearing particularly preferably has an axial extension dimension that corresponds to the axial extension dimension of other components of the shaft drive, for example, to the rotary bearing, particularly a ball bearing, between the shaft-driven generator or the flexible gear and the shaft-driven generator. Viewed radially and with respect to the axial extension dimension, the rotary bearing preferably completely overlaps with these components.

[0026] Several planes oriented perpendicular to the rotation axis have been described above, in which different components of the drive unit are arranged radially overlapping to reduce the axial extension of the drive unit along the rotation axis. Another such plane is the electronic equipment bearing plane, which is also oriented perpendicular to the rotation axis and contains a rotary bearing, particularly a ball bearing, and a control unit. If the drive unit is arranged around a crank, the rotary bearing is, for example, located between a fixed housing and the crank; or if the drive unit is mounted on a hub, the rotary bearing is located between a fixed housing component, such as a shaft, and the rotating hub housing. The electronic control unit will be discussed in more detail below. Regarding the optimal arrangement of the drive unit components relative to each other, it is preferable that the shaft support plane, the bearing plane of the flexible gear of the variable shaft drive, the transmission plane of the variable shaft drive, the symmetry plane, the transmission plane of the drive shaft drive, the bearing plane of the flexible gear of the drive shaft drive, and especially the electronic equipment bearing plane, are arranged sequentially along the rotation axis. This results in a particularly space-saving arrangement of the components.

[0027] As explained above, the drive unit, for example in a bicycle, can be located either centrally in the pedal area of ​​the frame or on one of the wheel hubs. In a preferred embodiment, the drive unit is configured as a centrally mounted drive unit, in which the rotation axis is arranged coaxially, particularly with the bottom bracket. Here, the drive unit is located, for example, between the pedals, and particularly between the pedal cranks. In this arrangement, the rotating axis, particularly the crank, passes through the drive unit, and the drive unit has a fixed housing. In a preferred alternative, the drive unit is configured as a hub-driven unit, in which the rotation axis is arranged coaxially, particularly with the wheel axle. That is, the drive unit is located on a wheel hub, for example, on the rear wheel. In this case, the drive unit is passed through by a fixed shaft and has a rotating hub housing that transmits rotational motion to the wheel via spokes. The drive unit is particularly preferably configured as a centrally mounted drive unit because a particularly good weight distribution is achieved by placing it centrally, for example, on the bicycle frame, resulting in a low center of gravity that is centrally located along the longitudinal axis.

[0028] It is always advantageous to design the axial extension dimension of the drive unit to be as small as possible. This is also advantageous when the drive unit is configured as a mid-drive unit, that is, located in the region of the central bearing shaft. As mentioned earlier, it is desirable that, based on average human anatomy, the crank arms of the vehicle pedals ideally have a spacing of 140-180 mm between each other. This can be ensured by the measures described above. Depending on the degree of consistency in implementing these measures, even smaller dimensions can be achieved. Thus, it is preferred that the extension dimension of the drive unit along the axis of rotation is at most 150 mm, preferably at most 135 mm, particularly preferably at most 120 mm, and especially, for example, at most 100 mm. The crank arms of the pedals should also preferably be spaced at most 200 mm between each other, particularly preferably at most 170 mm, and very particularly preferably at most 140 mm. In this way, comfortable and anatomically correct pedaling can also be achieved when the drive unit is configured as a mid-drive unit.

[0029] In a preferred embodiment, a control unit is provided for controlling the drive motor and / or the variable motor. The electronic control unit controls the motor's speed and / or direction of rotation and / or torque, specifically individually and independently. Here, the control unit also controls, for example, the settings of a continuously variable transmission (CVT) provided by the drive unit, such that comfortable pedaling is always achieved regardless of the current driving speed. For example, the control unit controls the motor through a stored rotational field, such as a three-phase rotational field. The motor's speed and torque characteristics are stored in this rotational field. The corresponding control of the motor is prior art and known to those skilled in the art, and therefore will not be described here. The control unit may have a range of different features and functions, as described below.

[0030] The control unit is structurally integrated into the drive unit. The drive unit, for example, is located in the bearing plane of the electronic device, perpendicular to the axis of rotation, along with the rotary bearing for the crankshaft. Therefore, the control unit is not simply externally connected to the drive unit, but rather nested within the transmission components of the drive unit, which helps to efficiently utilize structural space.

[0031] To control the function of the drive unit, different quantities reflecting the current operating state must be determined, and the control unit takes these quantities into account when controlling the motor. Thus, the control unit is connected, for example, to angle and / or speed and / or torque sensors on the input drive shaft. The input drive shaft is driven by the driver, for example, by pedaling, so the control unit can use the corresponding quantities to, for example, detect the driver's intentions, such as a higher pedaling frequency when the driver wants to accelerate. Furthermore, the control unit is preferably connected to a travel speed sensor, which is particularly located in or on the rear wheel hub, on the rear wheel or its spokes, or on the brake disc, and the travel speed sensor generally determines the vehicle's travel speed. A preferred embodiment sets the travel speed sensor integrated into the drive unit and mounted on the vehicle together with the drive unit. In this case, the travel speed is determined, for example, on the output driven shaft. This can be achieved particularly when the vehicle's drive wheels, such as the rear wheels, do not have their own flywheels and are rotated at the same speed as the drive wheels by a traction gear or sprocket on the drive unit. Using the driving speed sensor, the control unit can, for example, check whether the driving speed is higher or lower than the maximum speed, above which, for example, it is no longer permissible to transmit assistance from the motor to the output driven shaft, as explained above. In this case, the control unit assumes the corresponding control of the motor as described above. Furthermore, the control unit is preferably connected to speed and / or angle sensors, especially Hall sensors, on the drive motor and / or variable motor. The control unit is also preferably connected to a current intensity sensor for the drive motor and / or for the variable motor. The control unit can derive the corresponding torque of the motor from the current intensity. The control unit can then calculate the motor power together with the speed and adjust the power accordingly.

[0032] The primary function of the control unit is preferably to control the speed and torque of the drive motor and the variable motor, such that the accumulated drive energy or power, including energy or power from human muscle force, on the output driven shaft corresponds to the energy or power requirements of the drive unit. The corresponding energy or power requirements are determined by the control unit based on measurement signals provided to the control unit, taking into account the driver's pedaling behavior, which may, for example, derive from acceleration intention. The degree of motor-assisted assistance provided to the driver can be set on the control unit and taken into account by the control unit. The control unit preferably controls the speed of the drive motor proportionally to the travel speed, for example. In this way, the electric drive motor always bears the same proportion of the necessary drive energy or power at the total travel speed. Furthermore, it is preferable that the control unit activates drive assistance or braking functions according to the rotation direction of the shaft driven by human muscle force, such as a crank or input drive shaft. In this way, the drive unit achieves, for example, reverse pedaling braking, in which a braking command is derived from the driver's reverse pedaling. In this scenario, the control unit activates, for example, the switchable flywheel described earlier, and causes the drive motor to operate as a generator in order to recover kinetic energy into electrical energy, thereby braking the vehicle.

[0033] In electric-assist bicycles with rear-wheel suspension, there exists an effect known as pedal rebound or pedal bounce. This effect describes how, during each elastic bounce of the suspension system, the traction gear, such as a sprocket, automatically rotates. Consequently, the crank and crank arms also rotate with the pedals, causing discomfort to the rider. The control unit is now preferably configured to partially and, in particular, fully compensate for the pedal rebound caused by the vehicle's elastic bounce by manipulating a variable motor. For this purpose, the control unit is connected to a spring travel sensor of the vehicle, which in particular determines the elastic bounce itself and its magnitude, and sends the result to the control unit. By manipulating the variable motor, the control unit can rotate the crank and thus also the pedals. Based on the determined spring travel, the control unit is now configured to manipulate the variable motor such that it counteracts the movement of the crank caused by the pedal rebound. Thus, despite the elastic bounce of the rear wheel, the rotation of the pedals is suppressed. In principle, this compensation for pedal rebound can be achieved by any actuator that can affect the pedal position. Therefore, apart from the improvements to the design scheme specifically described in this application, this aspect constitutes a separate invention, independent of the structural and functional features of the embodiments described herein, and can be claimed separately.

[0034] The control unit can also be connected to a display unit to display information to the driver. The display unit can, in principle, be connected to the control unit via a cable and positioned anywhere on the vehicle, such as on the handlebars. However, it is preferred that the display unit is also housed within the drive unit's housing, and arranged such that it is visible from the outside through an observation window in the drive unit. Therefore, the display unit is preferably located on the side of the drive unit facing away from the road surface, i.e., on the upper side of the drive unit, together with the observation window. The observation window is made of a transparent material, such as glass or plastic. The display unit preferably includes at least one display showing information about the vehicle's operating status, such as current speed or battery level. The display is preferably configured to be light-emitting and includes, for example, LEDs. While the vehicle is in operation, the driver may, for example, look down at the drive unit and read the corresponding information on the display unit. The combination of the display unit and the observation window can, in principle, be implemented in any drive unit with electronic equipment. Therefore, apart from improvements to the design described specifically in this application, this aspect constitutes a separate invention, independent of the structural and functional features of the embodiments described herein, and can be claimed separately.

[0035] As already explained, the control unit can control the crank's rotational position and thus the pedal's rotational position by manipulating a variable motor. For example, when riding a bicycle, it is common practice that at least one pedal must be brought to a forward and upward oriented position each time the vehicle stops. That is, if viewed laterally, such that the forward direction corresponds to the clockwise rotation of the crank and pedal, one pedal should be brought to, for example, the two o'clock position. In this starting position, the rider can comfortably start and accelerate quickly. This positioning, traditionally set by the rider using the rear pedals, can also be set by the control unit. Preferably, the control unit manipulates the variable motor to bring the input drive shaft into the starting position. For example, this function is executed whenever the control unit detects that the vehicle has stopped. In this way, the vehicle is always automatically ready to start, without the rider needing to pay attention. This positioning of the pedals into the starting position can, in principle, be achieved by any actuator that can affect the pedal position. Therefore, apart from the improvements to the design scheme specifically described in this application, this aspect constitutes a separate invention, independent of the structural and functional features of the embodiments described herein, and can be claimed separately. Attached Figure Description

[0036] The present invention will now be described in detail with reference to the embodiments shown in the figures. Wherein, schematically:

[0037] Figure 1A side view of a vehicle with a mid-mounted drive unit is shown.

[0038] Figure 2 A side view of a vehicle with a hub drive unit is shown.

[0039] Figure 3 The external view, particularly the top view, of the central drive unit is shown;

[0040] Figure 4 An external view, particularly a top view, of the hub drive unit is shown;

[0041] Figure 5 A cross-sectional view of the shaft drive device is shown.

[0042] Figure 6 A cross-sectional view of the central drive unit along the axis of rotation is shown; and

[0043] Figure 7 A cross-sectional view of the hub drive unit along the axis of rotation is shown. Detailed Implementation

[0044] Identical or functionally equivalent components are labeled with the same reference numerals. Duplicate components are not labeled separately in each drawing.

[0045] Figure 1 and Figure 2 A vehicle F is shown, specifically a bicycle, particularly an electric-assisted bicycle. The vehicle can be driven simultaneously by an electric motor and human muscle force, particularly in such a way that the drive from human muscle force is assisted by the electric motor. The vehicle F includes a frame 73 and two running gears 72, specifically a front wheel and a rear wheel, in a known manner. A central axle 65 is provided at the middle and lower end of the frame 73. A wheel axle 66 is located at the connection point between the frame 73 and the rear wheel. Figure 1 The diagram illustrates one embodiment in which the drive unit 1 is configured as a centrally located drive unit situated on the central shaft 65. Human muscle force is directly introduced into the drive unit 1 via a crank. The transmission output of the drive unit 1 is configured as a traction gear 10 (see...). Figure 3 and 6 And, and connected to the rear wheel hub 2 via a traction component 3, such as a chain. According to Figure 2 In this embodiment, the drive unit 1 is configured as a hub drive unit and mounted on the axle 66. In this case, the transmission output end of the drive unit 1 is configured as a hub housing, and the rotational motion of the hub housing is transmitted to the rear wheel via spokes 59 (see...). Figure 4 and 7 The drive unit 1 is connected to the central shaft bearing 4 via the traction member 3, which introduces human muscle force into the drive unit 1.

[0046] Figure 3 and Figure 4 The top view of the drive unit 1 as seen from the outside is shown below. Figure 3 The drive unit 1, configured as a centrally located drive unit, is shown. The rotation axis 9 of the drive unit 1 is located on a central shaft 65, causing the crank arms 5 and pedals 6 of the vehicle F to rotate around the central shaft during pedaling motion. A traction gear 10 transmits the rotational motion to the rear wheel hub 2. The width of the drive unit 1 is indicated by B1. The distance between the crank arms 5 is indicated by B2. To achieve comfortable and anatomically sound pedaling, the distance B2 between the crank arms 5 should be between 140 and 180 mm. Therefore, the width B1 of the drive unit 1 must be correspondingly smaller. Furthermore, Figure 3 A control unit 42 integrated into the drive unit 1 is shown. The control unit 42 is connected to multiple sensors to detect the operating status of the drive unit 1 and the vehicle F, as will be described in detail below. Furthermore, the control unit 42 is connected to a display unit 70, such as a light-emitting display, which is visible from the outside of the drive unit 1. The display unit 70 is, for example, located behind an observation window in a housing outside the drive unit 1. Therefore, an operator seated in the vehicle F can see the display unit 70 by looking down. Figure 4 The diagram shows an implementation of drive unit 1 as a hub drive unit. Therefore, the rotation shaft 9 of drive unit 1 is located on axle 66, and the rear wheel rotates around said axle during the movement of the vehicle F. Rotation from pedal 6 is transmitted to drive unit 1 via traction gear 10. Drive unit 1, as a mid-mounted drive unit, is traversed by a rotating crank 32 (see...). Figure 6 The drive unit, which serves as the hub drive unit, passes through a fixed axle 11, around which the rear wheel rotates. A portion of the hub housing serves as the output end of the transmission device and thus as the output driven shaft 12. The hub housing rotates about the axle 11 and is non-rotatably connected to the spokes 59. The spokes 59 then transmit the rotational motion to the rest of the rear wheel.

[0047] Figure 5A transverse sectional view of the shaft drive devices 13, 18 as used in this invention is shown. The shaft drive devices 13, 18 are arranged around a rotating shaft 9 and include shaft-driven generators 16, 20, rotating bearings 17, 21, particularly (grooved) ball bearings, flexible gears 15, 19, and gear rings 14, 14'. Gear rings 14, 14' and shaft-driven generators 16, 20 are constructed as rigid members, while flexible gears 15, 19 are flexible or elastic. Shaft-driven generators 16, 20 are constructed in an elliptical shape, and flexible gears 15, 19 are supported on shaft-driven generators 16, 20 by rotating bearings 17, 21, such that flexible gears 15, 19 adapt to the elliptical shape of shaft-driven generators 16, 20 due to their elasticity. Gear rings 14, 14' have internal teeth, and flexible gears 15, 19 have complementary external teeth; flexible gears 15, 19 typically have fewer teeth than gear rings 14, 14'. The elliptical shape of the shaft-driven generators 16 and 20 presses the outer teeth of the flexible gears 15 and 19 into the inner teeth of the gear rings 14 and 14' along the main shaft of the shaft-driven generators 16 and 20. The elastic deformation of the flexible gears 15 and 19 simultaneously ensures that their outer teeth disengage from the inner teeth of the gear rings 14 and 14' along the secondary shaft of the shaft-driven generators 16 and 20. Now, if the shaft-driven generators 16 and 20 rotate, the flexible gears 15 and 19 reduce the speed by a reduction ratio i = Z. H / (Z H -Z F Rotate in the opposite direction of rotation, where Z H It refers to the number of teeth on gear rings 14 and 14', while Z... F This refers to the number of teeth on the flexible gears 15 and 19. If the flexible gears 15 and 19 are fixed, then the gear rings 14 and 14' rotate in the same direction as the shaft-driven generators 16 and 20 at a correspondingly reduced speed. Such shaft transmission devices 13 and 18 are cumulative transmission devices and are known in the prior art, so they need not be described in detail here.

[0048] Figure 6A cross-sectional view of drive unit 1 along rotation axis 9 or central axis 65 is shown, the drive unit being configured as a centrally located drive unit. Central axis 65 is defined by crank 32, which can be driven by the operator via pedal 6 and passes through drive unit 1 along rotation axis 9. Crank 32 is non-rotatably connected to input drive shaft 33, through which driving energy applied by the operator is introduced into the transmission of drive unit 1. The output end of the transmission is formed by output driven shaft 12, which is non-rotatably connected to traction gear 10, here a sprocket. Drive unit 1 has three sources of driving energy or driving power: on the one hand, human muscle force introduced through input drive shaft 33, and on the other hand, two motors 22, 27, specifically variable motor 22 and drive motor 27. The two motors 22, 27 are respectively integrated into the transmission system of drive unit 1 via shaft transmission devices 13, 18. Specifically, the variable motor 22 is connected to the transmission system via the variable shaft transmission device 13, while the drive motor 27 is connected to the transmission system via the drive shaft transmission device 18.

[0049] When the operator rotates crank 32 by pedaling foot 6, the input drive shaft 33 rotates. Input drive shaft 33 is connected to flexible gear 15 of variable shaft transmission 13 via flywheel 36. Flywheel 36 is configured such that it engages when input drive shaft 33 rotates in the forward direction, establishing a non-rotatable connection between input drive shaft 33 and flexible gear 15. Conversely, it rotates freely in the backward direction. Flexible gear 15 meshes with gear ring 14' of variable shaft transmission 13, rotating together with flexible gear 15 at a 1:1 transmission ratio. Gear ring 14' is also non-rotatably connected to output driven shaft 12, thus all driving energy introduced by the operator via pedaling foot 6 is transferred to output driven shaft 12 and from there to traction gear 10.

[0050] The variable motor 22 includes a stator 23 with stator windings 24. The stator 23 is mounted on a fixed support 43, which is, for example, tubularly arranged around a crank 32. Furthermore, the variable motor 22 includes a rotor 26 with permanent magnets 25. The rotor 26 of the variable motor 22 is non-rotatably, and particularly integrally, connected to the shaft-driven generator 16 of the variable shaft drive 13. Therefore, the variable motor 22 drives the shaft-driven generator 16 of the variable shaft drive 13. Depending on the rotational direction of the variable motor 22, the rotational speed of the gear ring 14' relative to the rotational speed of the input drive shaft 33 is switched differently. In this way, the transmission ratio between the input drive shaft 33 and the output driven shaft 12 can be steplessly adjusted. If the variable motor 22 rotates in the same direction as the input drive shaft 33, a faster switching occurs between the input drive shaft 33 and the output driven shaft 12, meaning that the output driven shaft 12 rotates faster than the input drive shaft 33. Accordingly, if the variable motor 22 rotates in the opposite direction to the input drive shaft 33, a slower transition is achieved between the input drive shaft 33 and the output driven shaft 12. In this case, the output driven shaft 12 rotates more slowly than the input drive shaft 33. Therefore, the variable motor 22, on the shaft-driven generator 16, and the input drive shaft 33, on the flexible gear 15, respectively form a transmission input end on the variable shaft transmission device 13. The gear ring 14' and the output driven shaft 12 form the transmission output end. The variable motor 22 and the variable shaft transmission device 13 form a stepless transmission between the input drive shaft 33 and the output driven shaft 12. Here, the gear ring 14' is formed at the accumulation point between the two transmission input ends.

[0051] The drive motor 27 also includes a stator 28 with stator windings 29 and a rotor 31 with permanent magnets 30. Similar to the variable motor 22, the stator 28 is mounted on a fixed support 43. The rotor 31 of the drive motor 27 is non-rotatably connected, in particular integrally connected, to the shaft-driven generator 20 of the drive shaft transmission 18. Therefore, the drive motor 27 drives the shaft-driven generator 20 of the drive shaft transmission 18. The rotation of the shaft-driven generator 20 transmits the driving energy of the drive motor 27 to the flexible gear 19. The flexible gear 19 is supported on a fixed housing component 56 by a flywheel 37. The driving energy is transmitted via the flexible gear 19 to the gear ring 14 of the drive shaft transmission 18. The gear ring 14 of the drive shaft transmission 18 is non-rotatably connected to the gear ring 14' of the variable shaft transmission 13, and is integrally constructed with it as a common gear ring 14, 14' for both shaft transmissions 13 and 18. In this common gear ring 14, 14', which is non-rotatably connected or integrally formed, the driving energy or driving power of the two motors 22, 27, as well as the human muscle force introduced through the crank 32, are accumulated and transmitted to the output driven shaft 12. The drive motor 27 is configured to provide the main part of the electric driving energy or driving power for the operation of the vehicle F. In order to drive the gear ring 14 in the forward direction, the shaft-driven generator 20 must also rotate in the forward direction. This results in the opposite direction of rotation of the flexible gear 19, i.e., rotation in the rearward direction. Therefore, in order for the driving energy to be transmitted from the shaft-driven generator 20 to the gear ring 14, the flexible gear 19 must be supported on the fixed housing component in the rearward direction. Therefore, the flywheel 37 is configured such that when the flexible gear 19 has a rearward rotation direction, the flywheel establishes a non-rotatable connection between the flexible gear 19 and the fixed housing component 56. This prevents the flexible gear 19 from rotating backward, thereby allowing all the driving energy applied by the drive motor 27 to the shaft-driven generator 20 to be transferred to the gear ring 14 and made available to drive the vehicle F.

[0052] Conversely, if the drive motor 27 is not running or is only running more slowly than, for example, by the operator rotating the gear ring 14 using muscle force, the output driven shaft 12 rotates the gear ring 14, and through the meshing of the gear ring with the flexible gear 19, the flexible gear 19 also rotates in the forward direction. However, in the direction of rotation of the flexible gear 19 corresponding to the forward travel direction, the flywheel 37 achieves free rotation, so that, in cooperation with the rotating bearing 21 between the flexible gear 19 and the shaft-driven generator 20, no driving energy is transmitted to the shaft-driven generator 20 and thus to the rotor 31 of the drive motor 27. Therefore, when pedaling with pure muscle force, it is not necessary for the rider to drag the drive motor 27, thereby achieving easy and comfortable pedaling of the pedals 6.

[0053] According to a preferred embodiment of the invention, the flywheel 37 is configured as a switchable flywheel. This means that the flywheel can be controlled by the control unit 42 in such a way that a non-rotatable connection is established between the flexible gear 19 and the fixed housing component 56 in both rotational directions. If the flexible gear 19 is thus locked in the forward rotational direction, the driving energy is transferred from the gear ring 14 to the shaft-driven generator 20 and thereby to the rotor 31 of the drive motor 27. Therefore, the drive motor 27 can then be operated as a generator and convert the rotational energy from the gear ring 14 into electrical energy, for example, that can be fed into a battery. By operating the drive motor 27 as a generator, the vehicle F can be braked, and this operation can also function as a brake. Furthermore, as explained above, the drive motor 27 can operate as a generator or in motor operation mode to negatively compensate for the driving energy or driving power introduced into the transmission system by the variable motor 22. For example, this is useful for complying with legal regulations that prohibit the transmission of drive power from motors 20 and 27 to the output driven shaft 12 from a predetermined maximum speed. By using a switchable flywheel 37 and negatively compensating for the power introduced by the variable motor 27 using the drive motor 27, the variable motor 22 can still be driven at speeds exceeding the legal maximum speed to provide a continuously variable transmission. The drive motor 27 then negatively compensates for the necessary output of drive energy to the transmission system.

[0054] The invention is characterized by a particularly narrow structural form along the rotation axis 9. For this purpose, the drive unit 1 includes a series of structural features, which will be discussed below. In one aspect, the invention uses two shaft drive devices 13, 18, which amplify the driving energy or power of the two motors 22, 27, and the driving energy or power from human muscle force in two gear rings 14, 14' that are non-rotatably connected or even integrally formed with each other. With this configuration of shared gear rings 14, 14', the two shaft drive devices 13, 18 can be arranged close to each other, thereby requiring very little construction space in the axial direction of the rotation axis 9.

[0055] The flexible gears 15 and 19 of the two shaft drive devices 13 and 18 are additionally configured to have sleeves 63 and 64. Sleeves 63 and 64 are cylindrical extensions of the flexible gears 15 and 19 extending axially along the rotation axis 9 from their engagement area with the gear rings 14 and 14'. At this time, viewed axially along the rotation axis 9, the two shaft drive devices 13 and 18 are located at the center of the drive unit 1, while sleeves 63 and 64 extend away from the shaft drive devices 13 and 18 and away from the center of the drive unit. Sleeves 63 and 64 are supported on fixed housing components, for example, on supports 43, at their axial ends opposite the engagement areas with the gear rings 14 and 14', respectively, by rotary bearings 45 and 48. In other words, viewed along the axial direction of the rotation axis 9, the flexible gears 15 and 19 extend from the transmission planes E1 and E1' perpendicular to the rotation axis 9 to the bearing planes E2 and E2'. In the transmission planes, the components of the shaft transmission devices 13 and 18, namely the shaft-driven generators 16 and 20, the rotating bearings 17 and 21, the flexible gears 15 and 19, and the gear rings 14 and 14', overlap in the radial direction of the rotation axis 9. In the bearing planes, the flexible gears 15 and 19 overlap with the rotating bearings 45 and 48 in the radial direction of the rotation axis 9. The flexible gears 15 and 19 each have a sleeve cavity 69 inside their hollow cylindrical bodies. To avoid leaving unused construction space, in the embodiment shown in this invention, the motors 22 and 27 are disposed in the corresponding sleeve cavities 69. Specifically, the variable motor 22 is disposed in the sleeve cavity 69 of the flexible gear 15 of the variable shaft transmission device 13, while the drive motor 27 is disposed in the sleeve cavity 69 of the flexible gear 19 of the drive shaft transmission device 18. The two motors 22 and 27 are disposed within the flexible gears 15 and 19, particularly within the corresponding sleeve cavities 69, along their stators 23 and 28 with stator windings 24 and 29, and rotors 26 and 31 with permanent magnets 25 and 30, along their entire axial extension. Furthermore, the motors 22 and 27 are disposed between the transmission planes E1 and E1' and the bearing planes E2 and E2'. Specifically, the variable motor 22 is disposed between the transmission plane E1' and the bearing plane E2', while the drive motor 27 is disposed between the transmission plane E1 and the bearing plane E2.

[0056] Another core concept of the invention is that by arranging the different rotary bearings and other components at the same height in the axial direction of the rotating shaft 9, the drive unit 1 is constructed to be particularly narrow in the axial direction of the rotating shaft 9. The various components of the drive unit 1 are thus nested together when viewed in the axial direction of the rotating shaft 9, as if the motors 22, 27 were nested with the shaft transmission devices 13, 18 by means of being housed within the sleeve cavity 69. For example, the rotary bearing 46, such as a ball bearing, for supporting the rotor 31 of the drive motor 27 relative to the fixed support 43, is arranged together with the drive shaft transmission device 18 in the transmission plane E1. For example, the rotary bearing 46 overlaps with other components of the drive shaft transmission device 18, such as the shaft-driven generator 20, the rotary bearing 21, the flexible gear 19, and the gear ring 14, along its entire axial extension in the direction of the rotating shaft 9. In this way, the rotary bearing 46 does not need to be constructed in axial series with these components of the drive shaft transmission device 18, thereby reducing the overall extension of the drive unit 1. The same applies to the rotary bearing 47 for the rotor 26 of the variable motor 22. The rotating bearing 47 is constructed exactly like the rotating bearing 46 and is arranged in a similar manner within the transmission plane E1' of the variable shaft transmission device 13.

[0057] Another implementation of this basic concept exists in the bearing planes E2 and E2'. In the bearing plane E2 of the flexible gear 19, viewed radially along the rotation axis 9, the rotary bearing 45 overlaps with the flywheel 37 between the flexible gear 19 and the fixed housing component 56, and the flexible gear 19 is supported on the fixed support 43 via this bearing. Similarly, viewed radially along the rotation axis 9, in the bearing plane E2' of the flexible gear 15, the rotary bearing 48 coincides with the flywheel 36 between the flexible gear 15 and the input drive shaft 33, and the flexible gear 15 is supported on the fixed support 43 via this rotary bearing. This also reduces the overall axial extension dimension of the drive unit 1.

[0058] Rotary bearings 49 and 50, preferably ball bearings, are disposed in a common shaft support plane E3 perpendicular to the rotation axis 9. Rotary bearing 49 is disposed between the input drive shaft 33 and the output driven shaft 12, and rotatably supports the input drive shaft and the output driven shaft relative to each other. Rotary bearing 50 is disposed between the output driven shaft 12 and the fixed housing component 57. Rotary bearings 49 and 50 are designed to be structurally identical (except for the necessary diameter difference), concentrically disposed around the rotation axis 9, and, when viewed in the radial direction of the rotation axis 9, completely overlap.

[0059] Another rotary bearing 44, located between the crank 32 and the fixed housing component 56, is situated in another electronic device bearing plane E4, perpendicular to the rotation axis 9. In this plane, the rotary bearing 44 at least partially overlaps with the control unit 42 in the radial direction of the rotation axis 9. Thus, the control unit 42 is not only externally mounted on the drive unit 1, but is configured to be nested with the transmission elements of the drive unit 1, thereby again saving axial extension dimensions. The control unit 42 is externally covered by the housing cover 55.

[0060] This achieves a particularly compact configuration, in which the shaft drive units 13, 18, and especially the flexible gears 15, 19, as well as the motors 22, 27, the rotary bearings 46, 47 for the rotors 26, 31, and the shaft-driven generators 16, 20 and flywheels 36, 37 opposite to the support 43 are constructed and arranged symmetrically about the plane of symmetry E5. Here, the plane of symmetry E5 is perpendicular to the axis of rotation 9 and is located between the shaft drive units 13, 18.

[0061] Control unit 42 is configured to control motors 22 and 27. To achieve the corresponding control functions, control unit 42 requires various measurements regarding the current operating states of drive unit 1 and vehicle F. For example, control unit 42 and... Figure 1 and 2 The spring travel sensor 67 and travel speed sensor 68 shown are connected, both of which are mounted on the rear wheels. Additionally, the control unit 42 is connected to a current intensity sensor 71, which measures the current intensity flowing in motors 22 and 27, respectively. The control unit 42 is additionally connected via circuit board 39 to a Hall sensor 38 on drive motor 27, and via circuit board 41 to a Hall sensor 40 on variable motor 22. Circuit boards 39 and 41 and Hall sensors 38 and 40 are also housed within their respective sleeve cavities 69 along with the corresponding motors 22 and 27. These sensors 38 and 40 allow the determination of the rotational speed and angular position of motors 22 and 27. Another sensor unit 51 and 52, connected to the control unit 42, has a fixed portion 52 on a fixed housing, such as a support 43, and a portion 51 that rotates with the input drive shaft 33. Sensor units 51 and 52 determine, for example, the torque applied to the crank 32 by human muscle force and thus to the input drive shaft 33, and determine the angular position. The rotational speed of crank 32 can also be determined from the time derivative at the angular position, and thus the rotational speed of input drive shaft 33 can be determined. The fixing part 52 of sensor units 51 and 52 is fixed to the support 43, especially by means of a fixing nut 53, and is fixed in particular in the area of ​​the support 43 supported relative to crank 32 by a rotating bearing 54, especially a needle roller bearing.

[0062] Figure 7 A cross-sectional view along the rotation axis 9 or wheel axle 66 is shown for a drive unit 1 configured as a hub drive unit. This configuration of drive unit 1 is largely similar to that of drive unit 1 configured as a mid-mounted drive unit. Therefore, only the differences from the above embodiment will be discussed. In particular, when drive unit 1 is configured as a hub drive unit, there is no crank 32 passing through drive unit 1. Instead, drive unit 1 is passed through by a fixed, upright shaft 11, which includes, for example, a support 43 and various fixed housing components 56, 57 and a plug housing 58 for electronic control unit 42. The input drive shaft 33 is not moved directly by pedal 6 or crank 32, but rather the pedal motion is transmitted to the input drive shaft 33 via traction member 3 and traction member gear 10. Meanwhile, the output driven shaft 12 is not connected to traction member gear 10, but is formed by a rotating hub housing with hub housing components 60, 61, which are non-rotatably connected to gear rings 14, 14'. The spokes 59 of the rear wheel are mounted on the hub housing components 60 and 61. Furthermore, the brake disc 62 is also mounted on the hub housing. In other respects, the embodiment of the drive unit 1 as a hub drive unit corresponds to the embodiment as a mid-mounted drive unit; therefore, to avoid repetition, refer to the description above.

[0063] In summary, the present invention enables the realization of a drive unit that is particularly compact in its axial extension dimension along the rotation axis 9. Furthermore, using the drive unit 1 according to the invention, multiple control functions desired in modern vehicles F, such as electric-assisted bicycles, can be configured.

Claims

1. Drive unit (1) for a vehicle (F) which can be driven simultaneously by drive energy provided by human muscle force and by an electric motor, comprising: - an input drive shaft (33) for transmitting drive energy generated by human muscle force, - an output driven shaft (12) for outputting drive energy to a running gear (72), - a drive shaft transmission (18) arranged about a rotation axis (9), which drive shaft transmission has a first shaft generator (20), a first flexible gear (19) and a ring gear (14), - an electric drive motor (27) having a stator (28) and a rotor (31) arranged about the rotation axis (9), the drive energy of which electric drive motor (27) can be transmitted via the drive shaft transmission (18) to the output driven shaft (12), - a variable shaft transmission (13) arranged in the drive train between the input drive shaft (33) and the output driven shaft (12), which variable shaft transmission has a second shaft generator (16), a second flexible gear (15) and a ring gear (14'), which variable shaft transmission (13) is arranged such that it receives drive energy from human muscle force of the input drive shaft (33) and transmits the drive energy to the output driven shaft (12) of the drive unit (1), - a variable electric motor (22) having a stator (23) and a rotor (26), the drive energy of which variable electric motor is likewise introduced into the variable shaft transmission (13), via which variable shaft transmission (13) the cumulative energy from human muscle force and the variable electric motor (22) can be transmitted to the output driven shaft (12), wherein the ring gear (14) of the drive shaft transmission (18) and the ring gear (14') of the variable shaft transmission (13) are configured to be rotationally fixed relative to one another and to transmit the cumulative drive energy from human muscle force, the electric drive motor (27) and the variable electric motor (22) to the output driven shaft (12). The variable shaft transmission (13) and / or the variable electric motor (22) are arranged about the rotation axis (9). The variable shaft transmission (13) constitutes a stepless transmission between the input drive shaft (33) and the output driven shaft (12). At least one of the flexible gears (15, 19) is configured as a sleeve (63, 64) which extends in the direction of the rotation axis (9), which sleeve is connected on one axial side to a rotational bearing (45, 48) and has a joint region for a shaft generator (16, 20) towards the other axial side, there being a sleeve inner chamber (69) between the rotational bearing (45, 48) and the shaft generator (16, 20) viewed in the direction of the rotation axis (9), and At least one of the electric motors (22, 27) is arranged at least partially in the sleeve inner chamber (69) of the shaft transmission (13, 18) assigned to the respective electric motor (22, 27) in the axial direction of the rotation axis (9). ​ ​ ​ 2. The drive unit (1) according to claim 1, characterized in that ​ 3. The drive unit (1) according to claim 1 or 2, characterized in that ​ 4. The drive unit (1) as claimed in claim 1 or 2, characterized in that ​ ​ 5. The drive unit (1) according to claim 1 or 2, characterized in that The shaft belt generator (16, 20), the flexible gear (15, 19) and the ring gear (14, 14') of the drive shaft transmission (18) and / or of the variable shaft transmission (13) are arranged one above the other in a transmission plane (El, El') perpendicular to the axis of rotation (9), and the flexible gear (15, 19) is rotatably mounted in a bearing plane (E2, E2') perpendicular to the axis of rotation (9) relative to the support (43), the drive motor (27) and / or the variable motor (22) being arranged between the transmission plane (El, El') and the bearing plane (E2, E2').

6. The drive unit (1) according to claim 1 or 2, characterized in that A rotational speed and / or rotational angle sensor (38, 40) is arranged on the drive motor (27) and / or on the variable motor (22).

7. The drive unit (1) according to claim 5, characterized in that The rotational bearing (50) for the output driven shaft (12) and the rotational bearing (49) for the input drive shaft (33) are arranged in a common shaft bearing plane (E3) perpendicular to the axis of rotation (9).

8. The drive unit (1) according to claim 1 or 2, characterized in that The variable motor (22) and the drive motor (27) are arranged coaxially with one another about the axis of rotation (9) and / or the variable shaft transmission (13) and the drive shaft transmission (18) are arranged coaxially with one another about the axis of rotation (9).

9. The drive unit (1) according to claim 7, characterized in that The shaft transmissions (13, 18) and the motors (22, 27) are arranged and constructed symmetrically to one another about a symmetry plane (E5) extending perpendicular to the axis of rotation (9).

10. The drive unit (1) according to claim 1 or 2, characterized in that The input drive shaft (33) is connected in a non-rotatable manner in at least one rotational direction to the flexible gear (15) of the variable shaft transmission (13), and the energy from the human muscle force is introduced into the variable shaft transmission (13) via the flexible gear (15).

11. The drive unit (1) according to claim 1 or 2, characterized in that The flexible gear (19) of the drive shaft transmission (18) is supported on a fixed housing part (56) by means of a freewheel (37).

12. The drive unit (1) according to claim 11, characterized in that The freewheel (37) is designed to be switchable or the flexible gear (19) and the fixed housing part (56) are connected in a non-rotatable manner by means of a separate clutch unit, so that the drive motor (27) can be operated as a generator which receives drive energy from the ring gear (14) and converts it into electrical energy.

13. The drive unit (1) according to claim 12, characterized in that The drive motor (27) is operated with an opposite and numerically identical drive power relative to the variable motor (22) from the maximum travel speed of the vehicle (F), so that the total drive power applied by the motors (22, 27) to the output driven shaft (12) is equal to zero.

14. The drive unit (1) according to claim 1 or 2, characterized in that A rotational bearing (45) is arranged in a bearing plane (E2) perpendicular to the axis of rotation (9) between the support (43) and the flexible gear (19) of the drive shaft transmission (18) and overlapping the freewheel (37), and / or A rotational bearing (48) is arranged in a bearing plane (E2') perpendicular to the axis of rotation (9) between the support (43) and the flexible gear (15) of the variable shaft transmission (13) and overlapping the freewheel (36). A rotational bearing (45) is arranged in a bearing plane (E2) perpendicular to the axis of rotation (9) between the support (43) and the flexible gear (19) of the drive shaft transmission (18) and overlapping the freewheel (37), and / or A rotational bearing (48) is arranged in a bearing plane (E2') perpendicular to the axis of rotation (9) between the support (43) and the flexible gear (15) of the variable shaft transmission (13) and overlapping the freewheel (36).

15. The drive unit (1) according to claim 1 or 2, characterized in that The shaft belt generators (16, 20), the flexsolls (15, 19) and the ring gears (14, 14') of the drive shaft transmission (18) and / or the variable shaft transmission (13) are arranged in a transmission plane (E1, E1') perpendicular to the rotation axis (9) together with the rotary bearings (46, 47) for the rotor (26, 31) of the drive motor (27) and / or the variable motor (22).

16. The drive unit (1) according to claim 9, characterized in that In the direction of the rotation axis (9), the shaft bearing plane (E3), the bearing plane (E2') of the flexsoll (15) of the variable shaft transmission (13), the transmission plane (E1') of the variable shaft transmission (13), the symmetry plane (E5), the transmission plane (E1) of the drive shaft transmission (18) and the bearing plane (E2) of the flexsoll (19) of the drive shaft transmission (18) are arranged in this order.

17. The drive unit (1) according to claim 1 or 2, characterized in that The drive unit (1) is configured as a mid-drive unit, or the drive unit (1) is configured as a hub drive unit.

18. The drive unit (1) according to claim 1 or 2, characterized in that The drive unit (1) has a maximum extension (B1) in the direction of the rotation axis (9) of 150 mm.

19. The drive unit (1) according to claim 1 or 2, characterized in that A control unit (42) is provided for controlling the drive motor (27) and / or the variable motor (22), which control unit has at least one of the following features: - The control unit is arranged in an electronics bearing plane (E4) perpendicular to the rotation axis (9) together with the rotary bearing (44) for the crank (32); - The control unit is connected to a rotation angle and / or rotation speed and / or torque sensor (51, 52) on the input drive shaft (33); - The control unit is connected to a travel speed sensor (68); - The control unit is connected to a rotation speed and / or rotation angle sensor (38, 40) on the drive motor (27) and / or on the variable motor (22); - The control unit is connected to a current intensity sensor (71) for the drive motor (27) and / or for the variable motor (22); - The control unit controls the rotation speed and the torque of the drive motor (27) and the variable motor (22) such that the drive energy, which includes the accumulation of energy from the human muscle force, on the output driven shaft (12) meets the energy requirements of the drive unit (1); - The control unit controls the rotation speed of the drive motor (27) in proportion to the travel speed; - The control unit (42) activates a drive assist function or a brake function depending on the direction of rotation of the shaft (32, 33) driven by the human muscle force; - The control unit is connected to a spring travel sensor (67) of the vehicle (F) and at least partially compensates for the pedal kickback due to the spring travel of the vehicle (F) by operating the variable motor (22); - The control unit is connected to a display unit (70), which is visible from the outside through an observation window in the drive unit (1); - The control unit brings the input drive shaft (33) into a starting position by operating the variable motor (22).

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