TECHNICAL FIELD

The invention relates to a torque transmission, wheel axle assembly, and hub assembly in particular for a bicycle.

BACKGROUND

Transmission systems, e.g. for vehicles, windmills etc., are known. In bicycles, especially racing bicycles, the transmission system traditionally includes a front derailleur and a rear derailleur, for shifting gears of the transmission system. An alternative to derailleurs is formed by gear hubs, where shifting of gears is accommodated by a gear shifting mechanism inside the, generally rear, wheel hub. A hybrid form is known where a gear hub torque transmission having at least two selectable gear ratios is coupled between the rear wheel hub and the rear sprocket. Herein the rear sprocket can include a cassette with a plurality of gear wheels, selectable through a rear derailleur. Here the gear hub can take the place of a front derailleur.

Such gear hub gear shifting mechanisms can include one or more planetary gear sets. The planetary gear includes at least three rotational members, such as a sun gear, a planet carrier and a ring gear. A clutch or brake system can be used for selectively coupling two of the rotational members, e.g. the planet carrier and the ring gear. When coupled, the hub gear shifting mechanism operates according to a first gear ratio. When decoupled, the hub gear shifting mechanism operates according to a second gear ratio.

WO202 1249945 discloses a transmission assembly, including a clutch or brake system and a planetary gear, wherein the clutch or brake system is arranged in the transmission assembly so as to selectively couple two of a sun gear, a planet carrier and a ring gear of the planetary gear.

US4157667 relates to a variable ratio drive which can be utilized for cycles, scooters, motorcycles, motor vehicles and any type of machine in general on which it is necessary to transmit motion with a multiphcative and/or a reducing ratio, with or without inversion of motion, from one to the other of two, coaxial or otherwise, rotating parts.

SUMMARY

It is an object to provide a torque transmission or transmission assembly which is cost-effective, can be manufactured with a small size, is easy to operate and/or is durable. Alternatively, or additionally, it is an object to provide a torque transmission or transmission assembly which can be operated under load, e.g. while pedalling. Alternatively, or additionally, it is an object to provide a torque transmission or transmission assembly which can be operated for coupling and for decoupling under load, e.g. while pedalling. Alternatively, or additionally, it is an object to provide a torque transmission or transmission assembly which can be operated both for upshifting and for downshifting under load, e.g. while pedalling. More in general it is an object to provide an improved torque transmission or transmission assembly, or at least an alternative torque transmission or transmission assembly.

A first aspect provides a transmission assembly according to claim 1.

When a driving part and a driven part of the actuator are rotatably mounted relative to the bicycle frame, the actuator may rotate for example around an axle of a wheel axle assembly. When the driving part and the driven part of the actuator are rotatably mounted relative to the bicycle frame, it may be more convenient for a controller of the actuator to receive a wireless control signal and to control the actuator based on such a wireless control signal, in particular when the controller of the actuator is surrounded by one or more components such as a wheel hub. Many components of a bicycle typically comprise materials which at least in part inhibit transmission of a wireless signal through said material, for example a metal. Additionally or alternatively, having a driving part and a driven part of the actuator rotatably mounted relative to the bicycle frame may allow for more freedom in designing the transmission assembly compared to using an actuator which is static also in use of the transmission assembly, and a transmission assembly with a smaller size may be obtained. Additionally or alternatively,

The actuator being rotatably mounted relative to the bicycle frame implies that in use, the actuator can be rotated relative to the bicycle frame. The rotation of the actuator relative to the bicycle frame may be around any axis of rotation, in particular an axis or rotation around which the bicycle frame itself does not rotate in use.

When the actuator for example is an electric motor, the driving part may be a stator of the motor, and the driven part may be a rotor of the motor.

When the torque transmission comprises a planetary gear, comprising a sun gear, a planet carrier and a ring gear, the actuator may be connected to rotate with the planet carrier. Since the planet carrier is typically positioned at a smaller radius than the ring, the tangential speed of the actuator may in use be lower when connected to the planet carrier compared to being connected to the ring. Additionally or alternatively, when the actuator is connected to rotate with the planet carrier, a torque transmission with a smaller size, for example a smaller outer footprint and/or smaller outermost radius, may be obtained. In other examples, the actuator may be connected to rotate with the ring of the planetary gear.

Whenever the torque transmission comprises the planetary gear comprising the sun gear, the planet carrier and the ring gear, one, more or all of the following features may apply to the planetary gear, in any combination. The sun gear may be partially or entirely positioned at a smaller radius than one or both of the planet carrier and the ring gear. The planet carrier may be partially or entirely radially positioned between the sun gear and the ring gear. The ring gear may be entirely or at least positioned radially further away from a rotation axis of the ring gear than the sun gear and/or the planet carrier. The ring gear, sun gear, and/or planet carrier may each be formed as a single integral body.

In general, when two objects such as the actuator and one of the sun gear, planet carrier, and the gear ring are connected to rotate with each other, it is implied that a rotation of a first of the objects results in a rotation of a second of the object by virtue of the objects being connected to each other, directly or indirectly. Two objects being connected to each other implies that at least one degree of freedom between the two objects is fixed or at least coupled with a particular stiffness and/or damping, in particular at least one rotational degree of freedom. Preferably, but not necessarily, the rotational speed of the two objects which are connected to rotate with each other is equal. However, for example using one or more gears, a non-unitary transmission ratio may be present between two objects which are connected to rotate with each other.

When two objects are rotatably mounted relative to each other or connected to rotate relative to each other, at least one rotational degree of freedom is allowed between said first and second objects.

In any example of a transmission assembly, the clutch or brake system may comprise:

-a first rotatable unit connectable to the input or output, including at least one first abutment surface;

-a second rotatable unit connectable to the output or input, respectively, including at least one second abutment surface arranged for selectively engaging the first abutment surface, the first and second abutment surfaces being adapted to each other so as to allow disengaging under load, e.g. in two directions; and

-a third rotatable unit including at least one retaining member, the third unit being arranged for selectively being in one of one or more first rotational positions or one of one or more second rotational positions relative to the second rotatable unit, wherein the at least one retaining member in a first rotational position locks the at least one second abutment surface in a first disposition for rotationally coupling the second unit to the first unit, and in a second rotational position releases the at least one second abutment surface to a second disposition.

In general, when the third rotatable unit is moved from a first rotational position to a second rotational position relative to the second rotatable unit, the third rotatable unit is rotated relative to the second rotatable unit about a rotation axis parallel to or even essentially aligned with the rotation axis of the input and/or output of the torque transmission and/or the rotation axis of the second rotatable unit.

When the clutch or brake system comprises a first rotatable unit, the actuator, in particular the driving part and the driven part thereof, may be connected to the first rotatable unit, or at least connected to rotate with the first rotatable unit - regardless of the clutch or brake system being engaged or disengaged.

When the clutch or brake system comprises a second rotatable unit, the actuator, in particular the driving part and the driven part thereof, may be connected to the second rotatable unit, or at least connected to rotate with the second rotatable unit - regardless of the clutch or brake system being engaged or disengaged.

The actuator may be configured for rotating the third rotatable unit relative to the first rotatable unit, or for rotating the third rotatable unit relative to the second rotatable unit. In the first option, a first of the driving part and the driven part of the actuator may be connected to the third rotatable unit, and a second of the driving part and the driven part may be connected to the first rotatable unit.

In general, the third rotatable unit can be rotated fully - i.e. 360 degrees and more - about its rotation axis. Any third rotatable unit disclosed herein may be approximately rotationally symmetric about its rotation axis. The rotation axis of any third rotatable unit disclosed herein may be parallel or even essentially aligned with the rotation axis of the input and/or output of the torque transmission.

In particular, the actuator may be configured for rotating the third rotatable unit relative to the first rotatable unit or for rotating the third rotatable unit relative to the second rotatable unit, about a rotation axis essentially parallel to a rotation axis of the input and/or output of the torque transmission.

When the clutch or brake system comprises a fourth unit configured to be immobile relative to the bicycle frame and including a selector, the third rotatable unit may comprise an actuation member arranged for being gripped by the selector for moving the third rotatable unit from a first position to a second position or from a second position to a first position relative to the second rotatable unit.

As a further option when the clutch or brake system comprises a fourth unit, the second rotatable unit may include a retractor member arranged for moving the actuation member out of engagement with the fourth unit, wherein the actuator is configured for moving, such as rotating, the retractor member relative to the third rotatable unit.

When the transmission assembly is for example used in conjunction with a rear wheel of a bicycle, the transmission assembly may further comprise a hub axle configured to be connected to the bicycle frame, in particular to a fork end or dropout at or near an outer end of a seat stay and/or chain stay. The transmission assembly may then further comprise a hub shell rotatably mounted relative to the hub axle and connected to the output of the torque transmission. When the transmission assembly comprises the hub shell, the torque transmission may be configured for selectively driving the hub shell according to one of the at least two transmission ratios and the actuator may be rotatably mounted relative to the hub axle. When the transmission assembly thus comprises a hub shell, the actuator may be connected to rotate with the hub shell. The actuator may be directly connected to the hub shell, for example using a clamped, bolted, screwed, glued, form-fitted, or any other type of connection, or any combination thereof allowing the actuator to corotate with the hub shell.

When the transmission assembly is for example used in conjunction with a crank drive of a bicycle, the transmission assembly may further comprise a crank shaft connected to the input of the torque transmission and a crank assembly housing, wherein the torque transmission and the clutch or brake system are mounted in or to the crank assembly housing. The actuator may then be rotatably mounted relative to the crank assembly housing.

Any embodiment of the transmission assembly may comprise at least part of a power source for powering the actuator. The power source may be rotatably mounted relative to the bicycle frame. Preferably, the power source is connected to rotate with the driving part of the actuator, for example to avoid a need for a slip ring to transfer power from the power source to the driving part of the actuator.

When the transmission assembly further comprises at least part of a power source for powering the actuator, the power source may be connected to rotate with the planet carrier or the ring gear when the torque transmission comprises a planetary gear. This may for example allow for powering an actuator which is also connected to rotate with the planet carrier or the ring gear, and/or to use rotational kinetic energy as an energy source for the power source. It particular, it may be advantageous to connect the actuator and the power source to rotate with the same planet carrier or ring gear.

The power source may be arranged to provide electrical power to the actuator, in particular when the actuator is an electric motor or other electrically operated actuator such as a solenoid switch. The electrical power may be supplied in a particular voltage and current corresponding to the voltage and current with which the actuator is arranged to operate. The power source may be or comprise a battery, supercapacitor, and/or ultracapacitor. The power source may for example be removably connected to the transmission assembly such that the power source may be replaced by a user.

When the power source is arranged for converting kinetic energy, in particular rotational kinetic energy, into electrical energy for powering the actuator, kinetic energy supplied to the torque transmission may be used for powering the actuator. Such kinetic energy may for example be supplied by a cyclist when the transmission assembly is used in a bicycle. In particular cases, no other power source such as a battery or supercapacitor is required when the power source is arranged for converting kinetic energy into electrical energy. However, for example as a backup power source when the power source has not been rotated for some time, a battery or supercapacitor may be used.

The at least part of the power source for powering the actuator comprised by the transmission assembly may be a rotor or stator of an electric generator. In general, an electric generator is used to convert kinetic energy into electrical energy. The kinetic energy may for example be supplied by a rider of a bicycle peddling, which causes a rotation of the input of the torque transmission. The electric energy generated using the electric generator may be directly used for powering the actuator and/or stored or temporary accumulated as chemical energy for use by the actuator, for example in a battery or supercapacitor.

When the transmission assembly further comprises an electronic controller for controlling the actuator, at least part of the electronic controller may be rotatably mounted relative to the bicycle frame. Compared to an electronic controller which is static - i.e. not rotating - in use of the torque transmission, having a rotating electronic controller may allow for the electronic controller to conveniently provide a control signal to an actuator which also rotates in use.

The electronic controller may comprise an electronic processor such as a CPU. The electronic processor is arranged for generating a control signal for controlling the actuator, and the electronic processor may be rotatably mounted relative to the bicycle frame. The control signal may for example be indicative of an engaging or disengaging of the clutch or brake system.

Additionally or alternatively, the electronic controller may comprise a printed circuit board (PCB), the printed circuit board being connected to rotate with the planet carrier or the ring gear. On the PCB, electronic components of the electronic controller may be affixed and connected via one or more conductive layers of the PCB.

As a particular option readily applicable for any electronic controller disclosed herein, the controller may comprise at least part of a signal receiver for receiving a control input signal, which at least part of the signal receiver is rotatably mounted relative to the bicycle frame. The control input signal may for example be indicative of an engaging or disengaging of the clutch or brake system. The control input signal may be provided by a user operated controller, such as a shifter, gear lever, or shift button, which for example may be attached to steering wheel of a bicycle for easy access for the user while cycling. In general, the control input signal may be transferred to the signal receiver via one or more wires, or as a wireless signal. When the control input signal is transferred via one or more wires, the signal may be an electronic signal transferred via one or more conductive wires, or the signal may be a mechanical signal, for example a change in mechanical tension on the one or more wires. In the latter case, a wire may for example be a shift cable.

As a particular example, the at least part of the signal receiver comprises an antenna arranged for receiving an electromagnetic control signal, for example a Bluetooth® signal. It may be advantageous to connect the actuator and/or the power source and/or the electronic controller, in any combination thereof, to corotate.

When the transmission assembly comprises a hub shell, the signal receiver may corotate with the hub shell. As such, for example when only part of the hub shell is arranged for having a wireless signal passed therethrough, this part of the hub shell may remain aligned with the signal receiver also when the hub shell rotates in use of the transmission assembly.

When the transmission assembly comprises a signal receiver with an antenna arranged for receiving an electromagnetic control signal, the antenna may be at least partially surrounded by the hub shell. As such, for example, the antenna may be at least partially protected from outside influences such as impacts or weather.

To allow a wireless signal, such as electromagnetic signals such as radio waves, to reach the antenna, at least with sufficient power to be properly received by the antenna, the hub shell may be at least partially permeable to the wireless signal, in particular part of the hub shell surrounding the antenna is permeable to the wireless signal, e.g. radio waves. For example, a part of the hub shell may form a window which is more permeable to the wireless signal, e.g. radio waves, than other parts of the hub shell surrounding or adjacent to said window.

In particular when the hub shell is at least partially permeable to the wireless signal, e.g. radio waves, another part of the hub shell may comprise electromagnetic shielding material, such as metal. Such electromagnetic shielding material may be used to provide strength and/or stiffness to the hub shell, and may be more suited to provide said strength and/or stiffness compared to materials which are more permeable to electromagnetic radiation.

The hub shell may for instance include a metal outer hub shell wall, while the window or the plurality of windows is formed by one or more apertures in the outer hub shell wall. The aperture(s) may be closed against dirt, debris and/or moisture, by a material permeable to the wireless signal, such as a plastic, resin, composite material or the like.

When the transmission assembly comprises the hub shell, the actuator may be connected to rotate with the hub shell. For example, the actuator may be directly or indirectly connected to the hub shell. In particular when the actuator is connected to rotate with the hub shell, the actuator may be partially surrounded by at least part of the hub shell.

As an option applicable for any transmission assembly disclosed herein, the clutch or brake system may be arranged for selectively coupling a planet carrier and a ring gear when the torque transmission comprises a planetary gear comprising said planet carrier and ring gear. For example, when the planet carrier and the ring gear are coupled, the rotational speed of the planet carrier is equal. When the planet carrier and the ring gear are uncoupled - i.e. allowed to rotate relative to one another - a non-unitary gear ratio may be obtained between the planet carrier and the ring gear.

When the transmission assembly comprises a hub axle configured to be connected to the bicycle frame, the transmission assembly may further comprise a stator or rotor arranged to form an electric generator with the respective rotor or stator of the power source, which stator or rotor is arranged to rotate with the hub axle. The hub axle may for example be a thru axle. In use, the hub axle may not rotate substantially, for example when the wheel axle is rigidly fixed to the bicycle frame, for example via a dropout.

In use, the hub axle may thus remain static, i.e. not rotating, whereas the rotor or stator comprised by the power source may rotates around the hub axle. As such, preferably, the power source comprises the rotor, and the stator is connected to the hub axle. The stator being connected to the hub axle implies that in use the stator does not rotate when the wheel axle also does not rotate. Any example of the transmission assembly may comprise a speed signal generator operatively connected to the rotor or stator, which speed signal generator is arranged for generating a speed signal indicative of a rotational speed of the rotor. The rotational speed of the rotor may be used to determine a speed of a bicycle, for example using an outer diameter of a wheel connected to corotate with the rotor. It will be appreciated that embodiments of transmission assembly comprising a speed signal generator are envisioned wherein at least one of the driving part and the driven part of the actuator are in use rotatably fixed relative to the bicycle frame. Thus, the speed signal generator may be applied to embodiments of the transmission assembly regardless of whether the driving part and the driven part of the actuator are rotatably mounted relative to the bicycle frame or not.

In general, the transmission assembly may comprise a driver body arranged for being coupled to a sprocket or cassette of sprockets. The driver body may be connected to an input of the torque transmission. When the transmission assembly comprises a planetary gear, the hub shell may be connected to rotate with a first of the ring gear and the planet carrier, and the driver body may be connected to rotate with a second of the ring gear and the planet carrier. As such, torque can be transferred between the driver body and the hub shell via the torque transmission. In particular, torque can be transferred from the driver body, via the ring gear and the planet carrier, to the hub shell.

Embodiment of the transmission assembly are thus envisioned wherein at least part of the actuator is housed inside the hub shell. Alternatively, at least part of the actuator may be housed inside the driver body when the transmission assembly comprises a driver body.

When the transmission assembly comprises a power source, said power source may be directly connected to the hub shell. The power source may additionally or alternatively be surrounded by at least part of the hub shell, for example to protect the power source from outside influences such as impacts or weather influences.

As an option applicable to any embodiment of the transmission assembly, the actuator may be positioned on an opposite side of the planetary gear than the driver body. In use, when the typical driving direction of a bicycle is regarded as a forward direction, the actuator may be positioned to the left of the planetary gear, and the driver body may be positioned to the rights of the planetary gear. When the actuator is positioned on an opposite side of the planetary gear than the driver body, more freedom may be obtained to design the driver body, for example to use a cylindrical driver body which is compatible with conventional cassettes of sprockets.

As a further option applicable to any embodiment of the transmission assembly, the actuator may be positioned on an opposite side of the torque transmission than the clutch or brake system. When the torque transmission comprises a planetary gear, the actuator may be arranged to selectively engaging or disengaging the clutch or brake system through the planetary gear. For example, part of the actuator, part of the clutch or brake system, and/or part of a connector connecting the actuator and the clutch or brake system may extend through the ring of the planetary gear, in particular in a space between the ring, sun, and one or more planets of the planetary gear.

A second aspect provides a hub assembly, such as for a bicycle, according to claim 33.

A third aspect provides a crank assembly, such as for a bicycle, according to claim 35.

A fourth aspect provides a clutch or brake system for use in a transmission assembly according to the first aspect.

A fifth aspect provides a hub assembly, such as for a bicycle, comprising a hub shell and an antenna for receiving and or transmitting a wireless signal positioned inside the hub shell, wherein the hub shell is at least partially permeable for the wireless signal. Thus, the antenna need not be placed outside the hub shell. The antenna inside the hub shell can be placed close to electronics placed inside the hub shell. It will be appreciated that the antenna may be immobile relative to the hub shell, i.e. rotate with the hub shell. Alternatively, the antenna may be immobile relative to a stationary axle of the hub assembly. The stationary axle can be configured to be connected to a frame of a bicycle.

Optionally, the hub shell may include a window, such as a plurality of windows, which is more permeable to the antenna signal than other parts of the hub shell surrounding or adjacent to said window. The hub shell may for instance include a metal hub shell wall, while the window or the plurality of windows is formed by one or more apertures in the hub shell wall. The aperture(s) may be closed against dirt, debris and/or moisture, by a material permeable to the wireless signal, such as a plastic, resin, composite material such as a carbon composite material, or the like.

Optionally, the hub shell may include a circumferential portion at least partially permeable for the wireless signal. The circumferential portion can include a ring shaped section of the hub shell. The circumferential portion can be of a material permeable to the wireless signal, such as a plastic, resin, composite material such as a carbon composite material or the like.

Optionally, the hub shell is of a material permeable to the wireless signal, such as a plastic, resin, composite material such as a carbon composite material or the like.

Optionally, The hub assembly includes a torque transmission having an input connected or connectable to a driver and/or one or more sprockets, and an output connected or connectable to a hub shell, wherein the torque transmission is configured for selectively driving the output according to one of at least two transmission ratios relative to the input. The hub assembly can include an actuator for switching the torque transmission from one transmission ratio to another. The actuator can be configured to be wirelessly operated on the basis of a wireless signal received by the antenna.

It shall be appreciated that aspects and options disclosed herein may be variously combined. For example, features described as relating to a transmission assembly may be correspondingly applied to the hub assembly, and vice versa.

BRIEF DESCRIPTION OF THE FIGURES

In the figures, exemplary embodiments are given by way of non- limitative illustration. It is noted that the figures are only schematic representations of embodiments of the invention that are given by way of nonlimiting example.

In the figures:

Fig. 1A shows in a schematic cross-section a hub or transmission assembly;

Fig. IB shows in a schematic cross-section part of a hub or transmission assembly;

Fig. 2 A shows a schematic view of the transmission or hub assembly 100 of Fig. 1A;

Fig. 2B shows an alternative transmission or hub assembly;

Fig. 3 shows an example of a clutch or brake system;

Fig. 4 shows an example of a clutch or brake system;

Fig. 5 shows an example of a clutch or brake system;

Fig. 6 shows an example of a clutch or brake system; and

Fig. 7 schematically shows a bicycle.

DETAILED DESCRIPTION

Fig. 1A shows in a schematic cross-section a hub or transmission assembly 100, for a bicycle with a bicycle frame. It will be understood that the assembly 100 may be mirrored at least in part over the axis 11, and for conciseness of the figures only at top half of the assembly 100 is depicted.

The assembly 100 comprises a hub shell 10, and a driver body 30. In particular, the driver body 30 may be a cylindrical driver body, although other shapes are envisioned for the driver body as well, for example a conical or frusto-conical shape. The hub shell 10 and the drive body 30 are rotatable about a wheel axle 11, which extends along a rotation axis A. In use, the wheel axle 11 is connected to a bicycle frame 1024, preferably rigidly connected, as very schematically indicated in Fig. 1A. The wheel axle may also be referred to as a hub axle.

The driver body 30 is arranged for receiving a cassette of sprockets 70 thereon. An axial spline may be provided on a perimeter of the driver body 30 for engaging a complementary spline of the cassette of sprockets, such as to transfer torque from the cassette to the driver body 30. The driver body 30 may particularly have an industry standard diameter, for being compatible with industry standard cassettes. The driver body 30 may also be provided with a standard axial spline for cooperating with standard cassettes. The driver body 30 may for example be provided with nine axial splines. The cylindrical driver body can e.g. be configured to be compatible with Uniglide, Hyperglide, Hyperglide+, XD, or Exa-Drive.

The assembly 100 comprises a torque transmission 40. The transmission 40 is selectively operable according to two or more transmission mission ratios. The torque transmission 40 acts between the driver body 30 and the hub shell 10. Hence, the driver body 30 is connectable to an input of the torque transmission, whereas an output of the torque transmission is connectable to the hub shell 10.

Here, the torque transmission 40 includes a planetary gear set including a sun gear 41, at least one planet carrier 42 carrying a planet gear 44, and a ring gear 43. The sun gear 41, planet carrier 42 and ring gear 43 are rotatable about the axis A. The hub shell 10 is in these examples coupled to the planet carrier 42, but it will be appreciated that the hub shell 10 may also be coupled or couplable to the sun gear 41 and/or ring gear 43. Hence, in these examples, the planet carrier 42 forms an output of the torque transmission 40. The sun gear 41 is connected to the axle 11 via unidirectional fourth clutch 64. It will be understood that the torque transmission 40 may herein also be referred to as the transmission.

The transmission 40 includes an actuatable clutch or brake system 1 for changing a transmission ratio of the torque transmission 40. Here, the clutch or brake system 1 in a coupled state effectively couples the ring gear 43 to the planet carrier 42, such that the ring gear 43 and the planet carrier 42 are rotatably fixed to each other. In the decoupled state, the clutch or brake system 1 decouples the ring gear 43 from the planet carrier 42, for allowing the ring gear 43 and the planet carrier 42 to rotate at different rotational speeds. Hence, in these examples, an input of the torque transmission may be considered to be formed by the ring gear 43 and/or the planet carrier 42. For example, in the decoupled state of the clutch or brake system 1, the input may be considered to be formed by the ring gear 43, whereas in the coupled state of the clutch or brake system 1, the input may be considered to be formed by both the ring gear 43 and the planet carrier 42. A non-exhaustive set of examples of clutch or brake systems 1 are depicted in Figs. 3-6.

The torque transmission 40 is in this example housed within a hub chamber 18. In this example, the hub chamber 18 is a sealed hub chamber. Here, the hub shell 10 defines the sealed hub chamber 18. Hence, in this example, the transmission 40 is entirely housed by the hub shell 10. It will be appreciated that the transmission 40 may also, e.g. partly, be housed by the driver body 30. The sealed hub chamber 18 is substantially conically shaped in these examples. A radius of the hub shell 10 from the axis A at the drive side is larger than a radius of the hub shell 10 at the non-drive side of the hub shell 10. The hub shell 10 is provided with a first spoke flange 71 at the drive side of the hub shell 10 and a second spoke flange 72 at the non-drive side of the hub shell 10. The first and second spoke flanges 71, 72 are arranged for attaching spokes of a wheel thereto. The first spoke flange 71 is in these examples at a larger radius from the axis A than the second spoke flange 72.

The assembly 100 here comprises an intermediate drive body 20. The intermediate drive body 20 operatively interconnects the driver body 30 and the torque transmission 40. The intermediate drive body 20 includes an input for connection to the driver body 30 and an output for connection to the transmission 40. The intermediate drive body output is internal to the sealed hub chamber 18. The intermediate drive body input may be internal to the sealed hub chamber 18 or external to the sealed hub chamber 18. Torque is transferred from the driver body 30 to the transmission 40 by the intermediate drive body 20. Here, the assembly 100 includes a first coupling mechanism 50 for coupling the driver body 30 to the intermediate drive body 20, and a second coupling mechanism 60 for coupling the transmission 40 to the intermediate drive body 20. The second coupling mechanism is internal to the sealed hub chamber 18. The first coupling mechanism 50 may be internal to the sealed hub chamber 18 or external to the sealed hub chamber 18.

The hub shell 10 is bearing mounted to the axle 11 by a first bearing 212 and a second bearing 13. In this example, the first bearing 212 and the second bearing 13 are arranged axially overlapping, here concentrically, with respect to the axis A. The first bearing 212 is provided at a smaller radius from the axis A than the second bearing 13. The intermediate drive body 20 or the driver body 30 may extend between the first bearing 212 and the second bearing 13, to reach from internal to the sealed hub chamber 18 to external to the sealed hub chamber 18 or vice versa. The hub shell is further bearing mounted to the axle by a third bearing 14. The third bearing 14 is axially spaced from the concentric first and second bearings 12, 13, at a non-drive side of the hub assembly 100. The driver body 30 can be bearing mounted to the axle 11 by the first bearing 212 and an additional fourth bearing 15 axially spaced from the concentric first and second bearings 12, 13. This minimizes the number of bearings of the assembly 100, and thus the overall weight. Alternatively, the driver body 30 can be bearing mounted to the axle 11 by the fourth bearing 15 and an additional fifth bearing 16, both being axially spaced from the concentric first and second bearings 12, 13. This allows for easy replacement of the driver body 30. The bearings described herein may be roller bearings.

In the example of figure 1A, the first coupling mechanism 50 is external to the sealed hub chamber 18. The first coupling mechanism here includes a first coupling 51, arranged at the input of the intermediate drive body 20. The first coupling 51 is in this example a unidirectional first clutch 51, such as a freewheel. The unidirectional first clutch 51 is arranged for transferring torque between the driver body 30 to the intermediate drive body 20 in only one rotation direction about the axis A, more specifically the forward drive direction. Hence, for example, the unidirectional first clutch 51 enables driver body 30 to drive the intermediate drive body 20 in a forward rotation direction about the axis A, but not in a backward rotation direction about the axis A. The unidirectional first clutch 51 hence also allows the intermediate drive body 20 to rotate in the forward direction at a larger rotational speed than the driver body 30, i.e. overrunning the unidirectional first clutch 51. The first coupling 51 may be detachable for allowing the cylindrical driver body to be detached from the hub shell 10, e.g. for replacement or service. Thereto the first coupling may e.g. also include a splined connection to the intermediate drive body 20.

In the example of figure 1A, the second coupling mechanism 60, at the output 22 of the intermediate drive body 20, includes a second coupling 62. The second coupling 62 is here a bidirectional second coupling 62, e.g. a detachable coupling such as a splined coupling or a fixed direct connection, coupling the intermediate drive body output to the ring gear 43 of the transmission. Hence, here, the ring gear 43 is drivable in rotation about the axis A by the driver body 30, via the intermediate drive body 20. In a decoupled state of the actuatable clutch or brake system 1, the ring gear 43 in turn drives the planet carrier 42 in rotation about the axis A at a reduced rotation speed compared to the ring gear 43. In a coupled state of the clutch or brake system 1, the ring gear 43 and the planet carrier 42 corotate about the axis A at an equal rotation speed.

The second coupling mechanism 60, at the output of the intermediate drive body 20, in this example includes a third coupling 63. The third coupling 63 is, here, arranged to couple the intermediate drive part 20 to an input of the clutch or brake system 1. Here, the third coupling 63 is a unidirectional third clutch 63, e.g. a freewheel clutch. The unidirectional third clutch 63 prevents lockup of the transmission 60 if the hub shell 10 is rotated in the backward rotation direction, e.g. when the bicycle is rolled rearwards, and the clutch or brake system 1 is in the coupled state, since the ring gear 43 is enabled to rotate faster backwards about the axis A than the planet carrier 42. The third unidirectional clutch 63 is accordingly overrun if the bicycle is rolled backwards, and the clutch or brake system 1 is in the coupled state.

An actuator 46 is provided for actuating the clutch or brake system 1. The actuator 46 is in Fig. 1A schematically indicated, and may for example be embodied as an electric motor. The actuator 46 is schematically depicted in Figs. 1A and IB as a single body, but it will be understood that the actuator comprises a driving member and a driven member, both rotatably mounted relative to the bicycle frame 1024.

In the particular example of Fig. 1A, the actuator 46 is arranged to rotate with the planet carrier 42 and the hub shell 10. It will be appreciated however that in other example the actuator 46 may be arranged to rotate with the ring gear 43, in particular when the hub shell 10 is connected to rotate with said ring gear 43. Referring to the clutch or brake system 1 displayed in Figs. 3-6, by means of the actuator 46, the third rotatable unit 10 can be rotated relative to the first rotatable unit 2. In other examples, by means of the actuator, the third rotatable unit 10 can be rotated relative to the second rotatable unit 4. It will be appreciated that thus in different examples, the actuator may corotate with the third rotatable unit 10, with the second rotatable unit 4, or with the first rotatable unit 2.

As schematically depicted in Fig. 1A, the assembly 100 comprises an electronics assembly 90, which may comprise any of at least part of a power source. For example, the electronics assembly may comprise a battery or capacitor for powering the actuator.

The electronics assembly 90 can comprise a rotor 91, which can form a generator together with a stator 92. In the example of Fig. 1A, the stator is connected or at least connected to be rotationally fixed with respect to the axle 11. In use, the stator may thus not rotate, while the rotor 91 rotates around the stator 92. The stator 92 and the rotor 91 can be at least partially axially aligned. When the rotor 91 rotates around the stator 92, the rotor and stator can form an electric generator for converting the rotation of the rotor into electrical energy. Such electrical energy may for example be used to power the actuator. The stator 92 and rotor 91 are also schematically depicted in Fig. 2B.

As a particular option, a speed signal generator not depicted in the figure may operatively connected to the rotor or the stator, which speed signal generator is arranged for generating a speed signal indicative of a rotational speed of the rotor. The rotational speed of the rotor relative to the stator may be indicative of a speed of a bicycle comprising the transmission assembly.

The electronics assembly 90 may comprise an electronic controller for controlling the actuator, which electronic controller may thus corotate with the actuator. This the electronic controller comprises an electronic processor such as a CPU, wherein the electronic processor is arranged for generating a control signal for controlling the actuator, the electronic processor being rotatably mounted relative to the bicycle frame. In particular, the electronic processor as part of the electronics assembly, can corotate with the actuator. As such, the control signal may be transferred to the actuator by virtue of a wired connection, or alternatively via a wireless connection.

As depicted in Fig. 1A, and generally regardless of whether the actuator is rotatably mounted relative to the bicycle frame, or the actuator is conceivable fixed relative to the bicycle frame, the actuator can be positioned on an opposite side of the torque transmission 40 than the driver body 30. As a further option, the actuator 46 is positioned on an opposite side of the torque transmission 40 comprising the planetary gear than the clutch or brake system 1.

Fig. IB shows a schematic cross-section of part of a transmission assembly 100. The example of the transmission assembly 100 of Fig. IB comprises an antenna 95 comprised by a controller for controlling the actuator 46. The antenna is an example of a signal receiver for receiving a control input signal 97, and can be rotatably mounted relative to the bicycle frame. In general, any embodiment and example of the transmission assembly 100 disclosed herein may comprise an antenna rotatably mounted relative to the bicycle frame. The control input signal 97 may be an electromagnet signal, for example sent by a user operated controller 98.

In the example of Fig. IB, the antenna 95 is mounted to corotate with the hub shell 10, and the antenna 95 is positioned in the hub chamber 18. In particular, the antenna 95 can be aligned with a window 96. The window 96 is formed by a part of the hub shell 10 which is at least partially permeable to radio waves to allow the antenna to receive a wireless signal. Because the antenna corotates with the hub shell 10, in use when the hub shell 10 rotates, the antenna rotates as well and can remain aligned with the window 96. The window 96 may be closed against dirt, debris and/or moisture, by a material permeable to the wireless signal, such as a plastic, resin, composite material such as a carbon composite material, or the like.

It will be appreciated that in general, embodiment of the assembly 100 are envisioned comprising a plurality of antennas, which may be aligned with a plurality of windows of the hub shells. A plurality of antennas may be advantageous for better reception of the wireless control signal 97, in particular in more orientations of the antenna 95 relative to the user controller 98. For example, when two antennas are provided, the antennas may be spaced 180 degrees apart relative to the rotation axis A. Any other number of antennas, for example three or more, are envisioned, which may be spaced at a constant angular interval.

The controller comprised by the electronics assembly 90 is in Fig. IB schematically shown sending a control signal 99 indicative of an engaging or disengaging of the clutch or brake system 1 to control the actuator 46. Engaging or disengaging of the clutch or brake system 1 in turn results in a change in transmission ratio of the torque transmission 40.

Fig. 2 A shows a schematic view of the transmission or hub assembly 100 of Fig. 1A. Fig. 2B shows an alternative transmission or hub assembly 100, wherein the first coupling 51 is now positioned between the intermediate drive body 20 and the ring gear 43.

In both the example of Fig. 2A and the example of Fig. 2B, the actuator 46 is connected to rotate with the planet carrier 42 and part of the clutch or brake system 1. Furthermore, at least part of the electronics assembly 90 - for example a power source - are connected to rotate with the actuator 46.

Figures 3, 4 and 5 show an example of a clutch or brake system 1. The clutch or brake system 1 of this example is for use in a transmission assembly of a bicycle, however, other fields of use can be envisioned. The clutch or brake system 1 has an input arranged for connection to a drive source, such as pedals or a chain/belt. The clutch or brake system has an output arranged for connection to a load, such as a rear wheel hub. The exemplary clutch or brake system 1 is operable under load between the input and the output, e.g. while pedalling. Hence, the clutch or brake system 1 can be coupled or decoupled under load. Here, the clutch or brake system is operable under load between the input and the output both during upshift and downshift of the torque transmission.

The clutch or brake system in Figures 3, 4 and 5 includes a first rotatable unit 2. The first rotatable unit 2 is arranged to be connected to the input (or output). Here, the first rotatable unit 2 is designed as a housing part of the clutch or brake system 1. The clutch or brake system 1 includes a second rotatable unit 4. The second rotatable unit 4 is arranged to be connected to the output (or input, respectively). The first rotatable unit 2 includes at least one first abutment surface 6. In this example, the first rotatable unit 2 includes nine first abutment surfaces 6, here evenly distributed along the perimeter of the first rotatable unit 2 at 40 degrees mutual spacing. The second rotatable unit 4 includes at least one second abutment surface 8. In this example, the second rotatable unit 4 includes three second abutment surfaces 8, here evenly distributed along the perimeter of the second rotatable unit 4 at 120 degrees mutual spacing. It will be appreciated that in this example the second rotatable unit 4 includes a plurality of gripping members 4a, here embodied as separate parts hingedly connected to a body portion 4b of the second rotatable unit 4. In this example, the second abutments surfaces 8 are part of the gripping members 4a of the second rotatable unit 4. The second abutment surfaces 8, here the gripping members 4a, are each arranged for selectively engaging one of the first abutment surfaces 6. In the example of Figure 3 it can be seen that the first and second abutment surfaces are oriented at an angle relative to a radial direction of the first and second rotatable units, respectively. This allows the first and second abutment surfaces to disengage under load. In this example, the second rotatable unit 4 includes resilient members 4c, here helical springs, arranged so as to bias the second abutment surfaces 8 out of engagement with the first abutment surfaces 6.

The clutch or brake system 1 in Figures 3, 4 and 5 includes a third rotatable unit 10. The third rotatable unit 10 is arranged for co-rotating with the second rotatable unit 4. That is, in use, when the output is rotating (e.g. when the driven wheel of the bicycle is rotating), i.e. when the second rotatable unit 4 is rotating, the third rotatable unit 10 generally co-rotates with the second rotatable unit 4.

In general, an actuator 46 may be provided which is connected to rotate with either the first rotatable unit 2 or the second rotatable unit 4. As such, the actuator 46 may be controlled to cause a rotation of said third rotatable unit 10 relative to the first rotatable unit 2 or the second rotatable unit 4, in particular a rotation about a rotation axis parallel to the rotation axis A of the hub shell 10 and the drive body 30, or even a rotation axis aligned with the rotation axis A of the hub shell 10 and the drive body 30. The actuator 46 may generally, for any actuator disclosed herein, be arranged to cause said rotation in one direction, or selectively also in opposite rotation directions. The actuator can e.g. include an electric motor with a rack and pinion unit.

The third rotatable unit 10 includes at least one retaining member 12. In this example, the third rotatable unit 10 includes three retaining members 12, here evenly distributed along the perimeter of the third rotatable unit 10 at 120 degrees mutual spacing. The third rotatable unit 10 is arranged for selectively being in a first position (see Figure 3) or a second position (see Figure 5) relative to the second rotatable unit 4. It will be appreciated that in this example the first position is a first rotational position, and the second position is a second, different, rotational position.

In the first position (shown in Figure 3), the retaining members 12 are positioned rotationally aligned with, here under, cams 4d of the gripping members 4a. Thus, in the first position, the gripping members 4a are forced to be pivoted in a radially outer position. In the first position, the second abutment surfaces 8 are positioned to be touching or close to the first abutment surfaces 6. The presence of the retaining members 12 under the cams 4a prevents the second abutment surfaces from being pivoted radially inwards sufficiently to disengage from the first abutment surfaces 6. Hence, the retaining members 12 in the first position lock the second abutment surfaces 8 in engagement with the first abutment surfaces 6. As the second abutment surfaces 8 are locked in engagement with the first abutment surfaces 6, the second rotatable unit 4 is rotationally coupled to the first rotatable unit 2.

In the second position (shown in Figure 5), the retaining members 12 are positioned rotationally not aligned with, here out of the reach of, the cams 4d of the gripping members 4a. Thus, in the second position, the gripping members 4a are free to pivot to a radially inner position. In this example, the biasing force of the resilient members 4c pivots the second abutment surfaces 8 radially inwards sufficiently to disengage from the first abutment surfaces 6. As a result, the first rotatable unit 2 is free to rotate independently of the second rotatable unit 4. Thus, the second rotatable unit 4 is decoupled from the first rotatable unit 2.

Hence, while the first abutment surfaces 6 and second abutment surfaces 8 are adapted to each other so as to allow disengaging under load, or to disengage under load, the relative positioning of the second rotatable unit 4 and the third rotatable unit 10 can selectively in the first position lock the second abutment surfaces 8 in engagement with the first abutment surfaces 6, and in the second position release the second abutment surfaces 8 for disengagement from the first abutment surfaces 6. It will be appreciated that while the first rotatable unit 2 and second rotatable unit 4 are decoupled, rotating the third rotatable unit 10 from the first position to the second position relative to the second rotatable unit 4, will couple the first and second rotatable units. While the first rotatable unit 2 and second rotatable unit 4 are coupled, rotating the third rotatable unit 10 from the second position to the first position relative to the second rotatable unit 4, will decouple the first and second rotatable units.

Changing the position of the third rotatable unit 10 relative to the second rotatable unit 4 from the first position to the second position, or vice versa, can be performed in many different ways, for example using an actuator connected to the third rotatable unit or second rotatable unit. Changing the position of the third rotatable unit 10 relative to the second rotatable unit 4 from the first position to the second position can be performed by rotating the third rotatable unit 10 relative to the second rotatable unit 4 in a forward direction, and changing the position of the third rotatable unit 10 relative to the second rotatable unit 4 from the second position to the first position can be performed by rotating the third rotatable unit 10 relative to the second rotatable unit 4 in an opposite, rearward direction. It is also possible to rotate the third rotatable unit 10 relative to the second rotatable unit 4 from the first position to the second position, and from the second position to the first position in one and the same rotational direction.

An actuator can thus be provided for rotating the third rotatable unit and/or the second rotatable unit from the first position to the second position, and/or from the second position to the first position. The actuator is elaborated on further in the present disclosure. Generally, in examples, the actuator, in particular a driving member and a driven member thereof, may in use corotate with the third rotatable unit or the second rotatable unit.

In the example of Figures 3, 4 and 5, the third rotatable unit 10 is arranged for co-rotating with the second rotatable unit 4. Therefore, changing the position of the third rotatable unit 10 relative to the second rotatable unit 4 from the first position to the second position, or vice versa, can be performed by temporarily changing rotation speed of the third rotatable unit relative to the second rotatable unit, e.g. by temporarily speeding up, braking or halting the second and/or third rotatable unit, for rotating from the first position to the second position, or from the second position to the first position, for example using the actuator 46.

In the example of Figures 3, 4 and 5, the third rotatable unit 10 can be freely rotatable relative to the second rotatable unit 4, in that there is no limit to the rotational displacement of the third rotatable unit 10 relative to the second rotatable unit 4. In this example, the third rotatable unit 10 is arranged for selectively being in one of a plurality of first positions or one of a plurality of second positions relative to the second rotatable unit. Each of the first positions of the plurality of first positions is defined by the third rotatable unit 10 being positioned to lock the second abutment surfaces 8 in engagement with the first abutment surfaces 6 for rotationally coupling the second rotatable unit 4 to the first rotatable unit 2. In this example there are three gripping members 4a and three retaining members 12, so there are three distinct first positions. Here, the three first positions are evenly distributed along the perimeter of the second rotatable unit 4 at 120 degrees mutual spacing. Each of the second positions of the plurality of second positions is defined by the third rotatable unit 10 being positioned to release the second abutment surfaces 8 from engagement with the first abutment surfaces 6 for rotationally decoupling the second rotatable unit 4 from the first rotatable unit 2. In this example there are three gripping members 4a and three retaining members 12, so there are three second positions. Here, the three second positions can be seen as evenly distributed along the perimeter of the second rotatable unit 4 at 120 degrees mutual spacing. It will be appreciated that the three first positions and three second positions are alternatingly placed along the perimeter of the second rotatable unit 4. For example, the three first positions and three second positions are alternatingly spaced at 60 degrees around the perimeter of the second rotatable unit.

Here, the third rotatable unit 10 can be rotated relative to the second rotatable unit 4 from a first first position to a first second position, from the first second position to a second first position, from the second first position to a second second position, from the second second position to a third first position, from the third first position to a third second position, and from the third second position to the first first position in one and the same rotational direction. The clutch or brake system 1 can be arranged for temporarily changing rotation speed of the third rotatable unit 10 relative to the second rotatable unit 4, e.g. by temporarily speeding up, braking or halting the second and/or third rotatable unit, for rotating from a first position (e.g. the first position or a first position of the plurality of first positions) to a second position (e.g. the second position or a second position of the plurality of second positions) or from a second position (e.g. the second position or a second position of the plurality of second positions) to a first position (e.g. the first position or a first position of the plurality of first positions). Hence, the second and third rotatable units can in a simple manner be rotated from a first position to a second position or vice versa, for example using the actuator 46.

Fig. 6 schematically depicts an example of a clutch or brake system 1 which can be comprised by any transmission assembly, hub assembly, and/or crank assembly disclosed herein, in the first position also elaborated on for example in conjunction with Fig. 3. The clutch or brake system 1 comprises the first rotatable unit 2, second rotatable unit comprising one or more gripping members 4a, and the third rotatable unit 10. In this position, the second rotatable unit 4 and the first rotatable unit 2 rotate together by virtue of the gripping members 4a engaging the abutment surfaces 6.

The clutch or brake system 1 comprises a plurality of retractor members 4e, but can conceivably also comprise only a single retractor member. The retractor member 4e is arranged to selectively allow an actuation member 210a to engage a groove 220, or knock the actuation member 210a out of the groove 220. The groove 220 is formed in a fourth unit 216. This fourth unit 216 is in use fixed relative to the bicycle frame. The rotational position of the retractor member 4e relative to the first rotatable unit 2 and/or second rotatable unit 4 can be controlled by an actuator. If the actuation member 210a engages the groove 220, the third rotatable unit 10 is stopped from rotating, while the first rotatable unit 2 and/or second rotatable unit 4 may continue in its rotation. Hence, the third rotatable unit 10 can be rotated relative to the first rotatable unit 2 and/or second rotatable unit 4. If subsequently the retractor member 4e is rotated relative to the first rotatable unit 2 and/or second rotatable unit 4 by the actuator, the retractor member 4e can be positioned to knock the actuation member 210a out of the groove 220, causing the third rotatable unit 10 to resume co-rotating with the first rotatable unit 2 and/or second rotatable unit 4. Using the actuator 46, the third rotatable unit 10 can thus be rotated relative to the first rotatable unit 2, or the third rotatable unit 10 can be rotated relative to the second rotatable unit 4 comprising the gripping members 4a. The actuator can e.g. include an electric motor, and optionally a rack and pinion for rotating the retractor member 4e relative to the first rotatable unit 2 and/or second rotatable unit 4.

Figure 7 shows a bicycle 1000, comprising a hub or torque assembly 100 as described herein. The bicycle 1000 comprises a frame 1024 with a front fork 1005 and a rear fork having a chain stay 1007, as well as a front wheel 1011 and a rear wheel 1013 located in the front and rear fork respectively. The bicycle 1000 further comprises a crank 1050, coupled to a front chain wheel 1019, wherein a chain 1023 threads over the front chain wheel 1019 and one of the sprockets of the cassette 74. A derailleur 1020 is provided for shifting the chain 1023 from one sprocket of the cassette 74 to another.

Herein, the invention is described with reference to specific examples of embodiments of the invention. It will, however, be evident that various modifications and changes may be made therein, without departing from the essence of the invention. For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, alternative embodiments having combinations of all or some of the features described in these separate embodiments are also envisaged.

In the example of Fig. IB, the antenna is mounted to corotate with the hub shell, and the antenna is positioned in the hub chamber aligned with the window. The window is formed by a part of the hub shell which is at least partially permeable to radio waves to allow the antenna to receive a wireless signal. Because the antenna corotates with the hub shell, in use when the hub shell rotates, the antenna rotates as well and can remain aligned with the window. It will be appreciated that it is also possible that the antenna is positioned immobile relative to the axle. By providing that the hub shell is at least partially permeable for the wireless signal, the wireless signal can also in that case reach the antenna. In case the antenna is positioned immobile relative to the axle, the hub shell may include a window, such as a plurality of windows, which is more permeable to the antenna signal than other parts of the hub shell surrounding or adjacent to said window. The hub shell may for instance include a metal hub shell wall, while the window or the plurality of windows is formed by one or more apertures in the hub shell wall. The aperture(s) may be closed against dirt, debris and/or moisture, by a material permeable to the wireless signal, such as a plastic, resin, composite material such as a carbon composite material, or the like.

Alternatively, or additionally, the hub shell may include a circumferential portion at least partially permeable for the wireless signal. The circumferential portion can for instance include a ring shaped section of the hub shell. The circumferential portion can be of a material permeable to the wireless signal, such as a plastic, resin, composite material such as a carbon composite material or the like. The hub shell can include metal end portions on either side of the circumferential portion. The spoke flanges can e.g. be positioned on the metal end portions, while the circumferential portion is positioned between the spoke flanges. Alternatively, or additionally, the hub shell is of a material permeable to the wireless signal, such as a plastic, resin, composite material such as a carbon composite material or the like.

It will be appreciated that also when the antenna is positioned immobile relative to the axle, the hub assembly can include a torque transmission having an input connected or connectable to a driver and/or one or more sprockets, and an output connected or connectable to a hub shell, wherein the torque transmission is configured for selectively driving the output according to one of at least two transmission ratios relative to the input. The hub assembly can include an actuator for switching the torque transmission from one transmission ratio to another. The actuator can be configured to be wirelessly operated on the basis of a wireless signal received by the antenna. At least part of the actuator can be positioned immobile relative to the axle. Also, control electronics of the actuator can be positioned immobile relative to the axle.

However, other modifications, variations, and alternatives are also possible. The specifications, drawings and examples are, accordingly, to be regarded in an illustrative sense rather than in a restrictive sense.

For the purpose of clarity and a concise description features are described herein as part of the same or separate embodiments, however, it will be appreciated that the scope of the invention may include embodiments having combinations of all or some of the features described.