Continuously variable transmission unit, such as for a bicycle

Abstract

The disclosure relates to a continuously variable transmission (CVT) unit (403). The CVT unit comprises a first input member (410) rotatable about a first axis (407) and a second input member (420) rotatable about a second axis (406) parallel to the first axis, wherein the first input member and the second input member are movable relative to each other in a direction transverse to the first and second axes. The CVT unit further comprises first coupling elements (411) provided at a constant first radius from the first axis and at a variable second radius from the second axis for transmitting torque between the first input member and the second input member.

Description

AREA

[0001] The invention relates to a continuously variable transmission unit, such as for a bicycle transmission. GENERAL STATE OF THE ART

[0002] Transmission systems, e.g., for vehicles, windmills, etc., are known. In bicycles, particularly racing bicycles, the transmission system conventionally includes a front derailleur and a rear derailleur for shifting gears of the transmission system. An alternative to derailleur systems is hub gears, in which gear shifting is achieved by a gear shifting mechanism within the wheel hub, generally located at the rear. A hybrid form is known in which a torque transmission of a hub gear with at least two selectable gear ratios is coupled between the rear wheel hub and the pinion. In this specification, the pinion can include a plurality of gears selectable by a rear derailleur. Here, the hub gear can take the place of a front derailleur.

[0003] Such a hub gear mechanism may include one or more planetary gear sets. The planetary gear mechanism includes at least three rotating elements, such as a sun gear, a planet carrier, and a ring gear. A clutch or brake system may be used to selectively couple two of the rotating elements, e.g., the planet carrier and the ring gear. In the coupled state, the hub gear mechanism operates according to a first gear ratio. In the uncoupled state, the hub gear mechanism operates according to a second gear ratio. SUMMARY

[0004] According to one aspect, a continuously variable transmission unit (CVT) is provided. The CVT unit can be used for various vehicles. The CVT unit includes a first input member rotatable about a first axis and a second input member rotatable about a second axis parallel to the first axis. The first input member and the second input member are movable relative to each other in a direction transverse to the first and second axes. The CVT unit includes first coupling elements provided at a constant first radius from the first axis and at a variable second radius from the second axis. The first coupling elements are provided for transmitting torque between the first input member and the second input member.The first input member and the second input member are movable relative to each other in a direction transverse to the first and second axes to transmit torque. By varying the relative displacement between the first axis and the second axis, the variable second radius in which torque is transmitted between the first and second input members is varied. Therefore, different gear ratios can be achieved between the first and second input members. Therefore, different gear ratios can be achieved between an input and an output of the CVT unit.

[0005] Optionally, at least one, or each, of the first coupling elements comprises a first and a second coupling body, and the first drive element comprises a first concentric guide extending concentrically around the first axis and having a first guide part on a first side of the second drive element and a second guide part on an opposite second side of the second drive element. In particular, the first guide part can extend on a first side of a first radial guide of the second drive element, and the second guide part can extend on an opposite second side of the first radial guide of the second drive element. Optionally, the first coupling elements can then be coupled to the second drive element in a tangential direction and movable relative to the second drive element in a radial direction.Thus, the first coupling elements can move radially relative to the second axis while remaining tangentially coupled to the second drive element. Optionally, the first coupling elements are coupled to the first drive element in a radial direction in the first radius and movable relative to the first drive element in a first tangential direction. In particular, the first and second coupling bodies can be coupled to the first and second guide parts in a radial direction in the first radius from the first axis and movable relative to the first and second guide parts in the first tangential direction. Optionally, the first coupling elements can be coupled to the first drive element in a second tangential direction opposite to the first tangential direction.In particular, the first and second coupling bodies can be coupled to the first and second guide parts in the second tangential direction opposite to the first tangential direction. Thus, the first coupling elements can be held at a predetermined radial distance relative to the first axis. The first coupling elements can, for example, be freely movable relative to the first drive element in the first tangential direction and coupled to the first drive element in the second tangential direction relative to the first drive element. Therefore, the first drive element can drive the first coupling elements in rotation in the first tangential direction, and the first drive element can move freely relative to the first coupling elements in the second tangential direction.The first coupling elements can also drive the first drive element in rotation in the second tangential direction, and the first coupling elements can move freely in the first tangential direction relative to the first drive element. Therefore, the first drive element can drive the second drive element in rotation in the first tangential direction, and the first drive element can move freely in the second tangential direction relative to the second drive element. The fact that the first coupling elements comprise the first and second coupling bodies, which can be coupled to the first guide part on the first side of the second drive element and to the second guide part on the opposite second side of the second drive element, can result in smooth operation of the gear unit with a reduced risk of jamming.

[0006] The first coupling body and the second coupling body of a first coupling element can be fixedly connected to one another. The first coupling body and the second coupling body of a first coupling element can be non-rotatably connected to one another. The first coupling body and the second coupling body of a first coupling element can be rigidly connected to one another. The first coupling body and the second coupling body can be connected via a bridge section. The first coupling body and the second coupling body of a first coupling element can be formed as a single part. This can apply to each first coupling element.

[0007] The first concentric guide may, for example, be one or more slots provided in the first drive element, the slot(s) extending concentrically around the first axis. The first guide part may, for example, be a first slot, and the second guide part may, for example, be a second slot. The first coupling body may comprise or be a first wedging body, and the second coupling body may comprise or be a second wedging body.

[0008] Optionally, the first concentric guide and the first coupling elements form or include a one-way coupling for enabling movement of the first coupling elements relative to the first concentric guide in the first tangential direction and for blocking movement of the first coupling elements relative to the first concentric guide in the second tangential direction. Each of the first coupling elements may, for example, comprise a one-way unit arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the first concentric guide when driven in the second tangential direction.

[0009] The first wedging body may, for example, be arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the first guide part when driven in the second tangential direction, and the second wedging body may, for example, be arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the second guide part when driven in the second tangential direction. Alternatively, the first wedging body may, for example, be arranged to clamp an inner and an outer surface of a circumferential wall of the first guide part when driven in the second tangential direction, and the second wedging body may, for example, be arranged to clamp an inner and an outer surface of a circumferential wall of the second guide part when driven in the second tangential direction.

[0010] Optionally, the first guide part and the second guide part are mutually connected at a radius that circumscribes the first coupling elements. The first guide part and the second guide part can be mutually connected at a radius that is greater than the constant first radius. The first guide part and the second guide part can form a one-piece part. Therefore, the first guide part and the second guide part can rotate together as one body. The first guide part and the second guide part can, for example, cover the first coupling elements and optionally the second drive element. The first guide part and the second guide part can be connected to form a closed cover. Therefore, moisture and / or dirt can be prevented from penetrating between the first drive element, the first coupling elements, and the second drive element.Optionally, the cover is connected to a bearing and / or a seal to completely enclose the second drive element and the first coupling element for protection against moisture and / or dirt. Alternatively, the first guide part and the second guide part are mutually connected at a radius circumscribed by the first coupling elements. The first guide part and the second guide part can be mutually connected at a radius that is smaller than the constant first radius. Therefore, the second drive element can be positioned radially outside the first drive element.

[0011] Optionally, each coupling body is configured to be in a neutral state, allowing free movement of the coupling body relative to the first concentric guide, and a coupled state, in which the coupling body is couplingly engaged with the first concentric guide. Therefore, in the neutral state, the coupling body may be freely movable relative to the first concentric guide, e.g., in one relative rotational direction, and in the coupled state, the coupling body may be couplingly engaged with the first concentric guide to transmit torque, e.g., in another relative rotational direction. For example, in the coupled state, the wedging body may be wedged between two circumferential walls of the first concentric guide, e.g., between a radially inner circumferential wall and a radially outer circumferential wall.

[0012] Optionally, each of the first and second coupling bodies is assigned at least one roller for coupling the coupling body to the first concentric guide.

[0013] Optionally, a first end of the coupling body is provided with a converging keying recess for engaging a first roller. The first roller can be positioned in the keying recess, e.g., between the coupling body and a surface of the first concentric guide. Alternatively or additionally, a second end of the coupling body, opposite the first end, can be provided with a diverging keying recess for engaging a second roller. The second roller can be positioned in the keying recess, e.g., between the coupling body and a surface of the first concentric guide. Here, converging and diverging are defined as viewed in a direction away from the center of the coupling body.With respect to a freewheeling direction of the wedging bodies, the converging wedging recess may be provided at a front end of the coupling bodies, and the diverging recess may be provided at a rear end of the coupling bodies. The first roller may, for example, be provided between a radially inner circumferential wall of the first concentric guide and a converging wedging surface of the converging coupling recess. The second roller may, for example, be provided between a radially outer circumferential wall of the first concentric guide and a diverging wedging surface of the diverging coupling recess. Optionally, the first and / or the second roller are preloaded in a wedging direction, e.g., elastically, e.g., with a spring. The first and / or the second roller may be preloaded toward the converging side of the coupling recesses.This provides the advantage that the coupling body is preloaded in a wedged state and can be released by movement in the freewheeling direction.

[0014] Optionally, the second drive element comprises first radial guides that extend at least radially with respect to the second axis, i.e., have a radial component. The first radial guides are arranged to guide movement of the first coupling elements in the radial direction and to transmit torque in the tangential direction. The first radial guides may comprise radially extending slots in a body of the second drive element.

[0015] Optionally, the first radial guides comprise a radially extending projection or recess, and the first coupling elements comprise a recess or projection configured to cooperate with the projection or recess of the first radial guide for axially aligning the first coupling elements with the second drive element.

[0016] Optionally, each of the first coupling elements includes a guide wheel for running along the first radial guides. The guide wheel allows the first coupling element to move radially inward and outward along the first radial guide while the guide wheel rolls along the first radial guide.

[0017] Optionally, each of the first coupling elements is associated with a support block for supporting the first radial guides. The support block allows the first coupling element to move radially inward and outward along the first radial guide while the support block slides and / or tilts along the first radial guide. Optionally, the support block has a rounded support surface for engaging the first radial guide. The rounded support surface facilitates sliding and / or tilting of the first coupling element. The rounded support surface can have a radius of curvature of 10-90 mm, such as 30-60 mm, e.g., 40-50 mm. The relatively large radius enables a relatively large torque transmission. Optionally, the support block pivots relative to the coupling element. The pivoting enables a smooth change of the CVT gear ratio under load. A pivot range can be, for example, 15 degrees, e.g., 10 degrees, such as, for example, 5 degrees.The support block may, for example, be positioned on, such as attached to, the bridge portion connecting the first and second coupling bodies. The first coupling element, e.g., the bridge portion, may have a rounded surface for abutting the support block to enable pivoting. Alternatively or additionally, the support block may have a rounded surface for abutting the first coupling element. The first coupling element may include one or more projections for holding the support block in place. Alternatively or additionally, the support block may include one or more projections for maintaining position relative to the first coupling element. The support block may be pivotally attached to the first coupling element. The support block may be flexibly attached to the first coupling element. The support block may be biased toward a neutral pivot position relative to the first coupling element.

[0018] Optionally, the first coupling elements are movably connected, such as hingedly, to the second drive element to enable radial movement of the first coupling elements relative to the second drive element.

[0019] Optionally, the first drive element may include or be connected to a pulley or a sprocket. Optionally, the second drive element may include or be connected to a pulley or a sprocket.

[0020] Optionally, the continuously variable transmission unit comprises a third input member rotatable about a third axis parallel to the second axis. The third input member and the second input member may be movable relative to each other in a direction transverse to the third and second axes. The CVT may include second coupling elements provided at a constant third radius from the third axis and at a variable fourth radius from the second axis for transmitting torque between the third input member and the second input member. Therefore, torque may be transmitted from the first input member to the second input member according to a first CVT gear ratio and from the second input member to the third input member according to a second CVT gear ratio.In particular, the first and second CVT gear ratios are arranged in series, and therefore, a gear ratio step of the CVT unit achievable with the CVT unit can be increased. Optionally, the constant first radius corresponds to the constant third radius, i.e., the constant first radius and the constant third radius are equal. Optionally, the variable second radius corresponds to the variable fourth radius, i.e., the variable second radius and the variable fourth radius are equal.

[0021] Optionally, each of the second coupling elements comprises a third and a fourth coupling body, and the third drive element comprises a second concentric guide extending concentrically around the third axis and having a third guide part on a first side of the second drive element and a fourth guide part on an opposite second side of the second drive element. In particular, the third guide part can extend on a first side of a second radial guide of the second drive element, and the fourth guide part can extend on an opposite second side of the second radial guide of the second drive element. The second coupling elements can be coupled to the second drive element in a tangential direction and movable relative to the second drive element in a radial direction.Thus, the second coupling elements can move radially relative to the second axis while remaining tangentially coupled to the third drive element. Optionally, the second coupling elements are coupled to the third drive element in a radial direction at the constant third radius and movable relative to the third drive element in a fourth tangential direction. In particular, the third and fourth coupling bodies can be coupled to the third and fourth guide parts in a radial direction at the third radius from the third axis and movable relative to the third and fourth guide parts in the fourth tangential direction. Optionally, the second coupling elements can be coupled to the third drive element in a third tangential direction opposite to the fourth tangential direction.In particular, the third and fourth coupling bodies can be coupled to the third and fourth guide parts in the third tangential direction opposite to the fourth tangential direction. Optionally, the third tangential direction corresponds to the first tangential direction, i.e., the third and first tangential directions are the same. Optionally, the fourth tangential direction corresponds to the second tangential direction, i.e., the fourth and second tangential directions are the same. Thus, the second coupling elements can be coupled to the third drive element in a radial direction in the third radius and movable relative to the third drive element in the second tangential direction, and the second coupling elements can be coupled to the third drive element in the first tangential direction.Therefore, the second coupling elements can drive the third drive element in rotation in the first tangential direction, and the second coupling elements can move freely in the second tangential direction relative to the third drive element. Therefore, the second drive element can drive the third drive element in rotation in the first tangential direction, and the second drive element can move freely in the second tangential direction relative to the third drive element. Also, the third drive element can drive the second coupling elements in rotation in the second tangential direction, and the third drive element can move freely in the first tangential direction relative to the second coupling elements.The fact that the second coupling elements comprise the third and fourth coupling bodies, which can be coupled to the third guide part on the first side of the second drive element and to the fourth guide part on the opposite second side of the second drive element, can result in smooth operation of the transmission unit with a reduced risk of blocking.

[0022] The third coupling body and the fourth coupling body of a second coupling element can be fixedly connected to one another. The third coupling body and the fourth coupling body of a second coupling element can be non-rotatably connected to one another. The third coupling body and the fourth coupling body of a second coupling element can be rigidly connected to one another. The third coupling body and the fourth coupling body can be connected via a bridge section. The third coupling body and the fourth coupling body of a second coupling element can be formed as a single part. This can apply to every second coupling element.

[0023] The second concentric guide may, for example, be one or more slots provided in the third drive element, the slot(s) extending concentrically around the third axis. The third guide part may, for example, be a third slot, and the fourth guide part may, for example, be a fourth slot. The third coupling body may be a third wedging body, and the fourth coupling body may be a fourth wedging body.

[0024] Optionally, the second concentric guide and the second coupling elements form or include a one-way coupling for enabling movement of the second coupling elements relative to the second concentric guide in the fourth tangential direction and for blocking movement of the second coupling elements relative to the second concentric guide in the third tangential direction. Each of the second coupling elements may, for example, comprise a one-way unit arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the second concentric guide when driven in the third tangential direction. The third wedging body may, for example,be arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the third guide part when driven in the third tangential direction, and the fourth wedging body can, for example, be arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the fourth guide part when driven in the third tangential direction. Alternatively, the third wedging body can, for example, be arranged to clamp an inner and an outer surface of a circumferential wall of the third guide part when driven in the third tangential direction, and the fourth wedging body can, for example, be arranged to clamp an inner and an outer surface of a circumferential wall of the fourth guide part when driven in the third tangential direction.

[0025] Optionally, the third guide part and the fourth guide part are mutually connected at a radius that circumscribes the second coupling elements. Therefore, the third guide part and the fourth guide part can rotate together as a single body. The third guide part and the fourth guide part can, for example, cover the second coupling elements and optionally the second drive element. The third guide part and the fourth guide part can be connected to form a closed cover. Therefore, moisture and / or dirt can be prevented from penetrating between the third drive element, the second coupling elements, and the second drive element. Optionally, the cover is connected to a bearing and / or a seal to completely enclose the second drive element and the second coupling element to shield them against moisture and / or dirt.Alternatively, the third guide part and the fourth guide part are mutually connected within a radius defined by the second coupling elements. Therefore, the second drive element can be positioned radially outside the third drive element.

[0026] Optionally, each coupling body is configured to be in a neutral state, in which free movement of the coupling element relative to the second concentric guide is enabled, and a coupled state, in which the coupling body is couplingly engaged with the second concentric guide. Therefore, in the neutral state, the coupling body can be freely movable relative to the second concentric guide, e.g., in one relative rotational direction, and in the coupled state, the coupling body can be couplingly engaged with the second concentric guide for transmitting torque, e.g., in another relative rotational direction. For example, in the coupled state, the wedging body can be wedged between two circumferential walls of the second concentric guide, e.g., between a radially inner circumferential wall and a radially outer circumferential wall.

[0027] Optionally, each of the third and fourth coupling bodies is assigned at least one roller for coupling the coupling body to the second concentric guide.

[0028] Optionally, a first end of the coupling body is provided with a converging coupling recess for cooperating with a first roller. The first roller can be positioned in the wedging recess, e.g., between the coupling body and a surface of the second concentric guide. Alternatively or additionally, a second end of the coupling body, opposite the first end, can be provided with a diverging wedging recess for cooperating with a second roller. The second roller can be positioned in the wedging recess, e.g., between the coupling body and a surface of the second concentric guide. With respect to a freewheeling direction of the wedging bodies, the converging wedging recess can be provided at a front end of the wedging bodies, and the diverging recess can be provided at a rear end of the wedging bodies.The first roller can be provided, for example, between a radially inner circumferential wall of the second concentric guide and a converging wedging surface of the converging coupling recess. The second roller can be provided, for example, between a radially outer circumferential wall of the second concentric guide and a diverging wedging surface of the diverging coupling recess. Optionally, the first and / or the second roller are preloaded in a wedging direction, e.g., elastically, e.g., with a spring. The first and / or the second roller can be preloaded toward the converging side of the coupling recesses. This provides the advantage that the coupling body is preloaded in a wedged state and can be released by movement in the freewheeling direction.

[0029] Optionally, the second drive element comprises second radial guides extending radially relative to the second axis, wherein the second radial guides are arranged to guide movement of the second coupling elements in the radial direction and to transmit torque in the tangential direction. The second radial guides may comprise radially extending slots in a body of the second drive element.

[0030] Optionally, the second radial guides comprise a radially extending projection or recess, and the second coupling elements comprise a recess or projection configured to cooperate with the projection or recess of the second radial guide for axially aligning the second coupling elements with the second drive element.

[0031] Optionally, each of the second coupling elements includes a guide wheel for running along the second radial guides. The guide wheel allows the second coupling element to move radially inward and outward along the second radial guide while the guide wheel rolls along the second radial guide.

[0032] Optionally, each of the second coupling elements is associated with a support block for supporting the second radial guides. The support block allows the second coupling element to move radially inward and outward along the second radial guide while the support block slides and / or tilts along the second radial guide. Optionally, the support block has a rounded support surface for engaging the second radial guide. The rounded support surface facilitates sliding and / or tilting of the second coupling element. The rounded support surface can have a radius of curvature of 10-90 mm, such as 30-60 mm, e.g., 40-50 mm. The relatively large radius enables a relatively large torque transmission. Optionally, the support block pivots relative to the coupling element. The pivoting enables a smooth change of the CVT gear ratio under load. A pivot range can be, for example, 15 degrees, e.g., 10 degrees, such as, for example, 5 degrees.The support block may, for example, be positioned on, such as attached to, the bridge portion connecting the third and fourth coupling bodies. The second coupling element, e.g., the bridge portion, may have a rounded surface for abutting the support block to enable pivoting. Alternatively or additionally, the support block may have a rounded surface for abutting the second coupling element. The second coupling element may include one or more projections for holding the support block in place. Alternatively or additionally, the support block may include one or more projections for maintaining position relative to the second coupling element. The support block may be pivotally attached to the second coupling element. The support block may be flexibly attached to the second coupling element. The support block may be biased toward a neutral pivot position relative to the second coupling element.

[0033] Optionally, the second coupling elements are movably connected, such as hingedly, to the second drive element to enable radial movement of the second coupling elements relative to the second drive element.

[0034] Optionally, the first axis and the third axis coincide. For example, the first drive element and the third drive element can be rotatable about a common axis.

[0035] Optionally, the second drive element is pivotally movable about a pivot axis extending parallel to the first and second axes for pivotal movement relative to the first drive element in a direction transverse to the first and second axes. Therefore, the second drive element can be moved relative to the first drive element about the pivot axis by a rotary drive.

[0036] Optionally, the transmission unit comprises a second gear concentrically coupled to the second drive member and rotatable therewith about the second axis; and a first gear drivingly connected to the second gear for transmitting torque between the first and second gears, the first gear having a rotational axis coincident with the pivot axis. For example, the first gear and the second gear may be a first gear and a second gear, respectively, the first and second gears meshing with each other to transmit torque. Alternatively, the first gear and the second gear may be a first chainring and a second chainring, respectively, connected by a chain.

[0037] Optionally, the transmission unit comprises an endless drive element, e.g., a chain or belt, drivingly engaging the first gear and the second gear, for transmitting torque between the first and second gears. A gearless transmission unit can therefore be achieved. Also, for example, when the first drive element is driven in rotation about the first axis, the driving force is transmitted through the first coupling elements to the second drive element. This force acts on the second drive element in substantially the opposite direction as a reaction force from the endless drive element. Therefore, an actuating force for moving the second drive element relative to the first drive element can be reduced, at least with respect to a drive arrangement with gears.

[0038] Optionally, the gear unit is arranged to pivot the second drive element between a concentric position in which the first and second axes coincide and an eccentric position in which the first and second axes are offset, and wherein, if the first drive element drives the second drive element in a driven direction of rotation about the second axis, the gear unit is arranged to pivot the second drive element from the concentric position to the eccentric position in a direction of rotation about the pivot axis opposite to the driven direction of rotation; and if the second drive element drives the first drive element in a driven direction of rotation about the first axis, the gear unit is arranged to pivot the second drive element from the concentric position to the eccentric position in the driven direction of rotation about the pivot axis.Therefore, an operating force for moving the second drive element relative to the first drive element can be minimized.

[0039] Optionally, e.g., alternatively or additionally, the first drive element is pivotally movable about a pivot axis extending parallel to the first and second axes for pivotally moving relative to the second drive element in a direction transverse to the first and second axes.Then, the gear unit can be arranged to pivot the first drive element between a concentric position in which the first and second axes coincide and an eccentric position in which the first and second axes are offset, and wherein, if the second drive element drives the first drive element in a driven rotational direction about the second axis, the gear unit can be arranged to pivot the first drive element from the concentric position to the eccentric position in a rotational direction about the pivot axis opposite to the driven rotational direction; and if the first drive element drives the second drive element in a driven rotational direction about the first axis, the gear unit can be arranged to pivot the first drive element from the concentric position to the eccentric position in the driven rotational direction about the pivot axis.Therefore, an operating force for moving the first drive element relative to the second drive element can be minimized.

[0040] Optionally, the gear unit comprises a pivot arm for coupling the first gear to the second gear and defining a constant distance between the second axis and the pivot axis, the pivot arm extending between a first end, at which the pivot arm couples to the first gear at the pivot axis, and a second end, at which the pivot arm couples to the second gear at the second axis. Since the first gear is rotationally associated with the pivot axis and the second gear is associated with the second axis, the first and second gears can remain drivingly engaged while the second gear is pivoted together with the second drive element relative to the first gear, e.g., directly meshingly engaged or via an endless drive element such as a belt or chain.

[0041] Optionally, the gear unit comprises a fourth gear concentrically coupled to the second drive member and rotatable therewith about the second axis; and a third gear drivingly connected to the fourth gear for transmitting torque between the third and fourth gears, the third gear having a rotation axis coincident with the pivot axis.

[0042] Optionally, a torque transmission between the first and second gear wheels defines a first transmission path, and a torque transmission between the third and fourth gear wheels defines a second transmission path parallel to the first transmission path; and the transmission system comprises a clutch for switching the torque transmission from the first transmission path to the second transmission path and / or vice versa. The clutch may, in particular, be a powershift clutch arranged for shifting under load, as described, for example, in WO2018 / 199757A2, WO2020 / 085911A2, or WO2021 / 080431A1, which are incorporated herein by reference.

[0043] According to one aspect, a hub assembly and / or a crank assembly for a bicycle is provided, comprising a continuously variable transmission unit as described in this document.

[0044] Optionally, the hub assembly comprises a hub shell for coupling to a driven wheel of the bicycle, the hub shell coupled to the first drive member and co-rotatable about the first axis; and a sprocket concentrically coupled to the second drive member and co-rotatable about the second axis. Alternatively, the hub assembly comprises a hub shell for coupling to a driven wheel of the bicycle, the hub shell coupled to the second drive member and co-rotatable about the second axis; and a sprocket concentrically coupled to the first drive member and co-rotatable about the first axis.

[0045] Optionally, the hub assembly comprises a hub shell for coupling to a driven wheel of the bicycle, the hub shell coupled to the first drive member and rotatable therewith about the first axis; and a sprocket coupled to the third drive member and rotatable therewith about the third axis.

[0046] Optionally, the crank assembly further comprises a first transmission, wherein the continuously variable transmission unit and the first transmission are connected in series; wherein the first transmission is selectively operable according to a first gear ratio or a second gear ratio and has a first clutch for switching the first transmission from the first gear ratio to the second gear ratio and / or vice versa.

[0047] Optionally, the crank assembly further comprises a second transmission, wherein the continuously variable transmission unit, the first transmission, and the second transmission are connected in series; wherein the second transmission is selectively operable according to a third gear ratio or a fourth gear ratio and has a second clutch for switching the second transmission from the third gear ratio to the fourth gear ratio and / or vice versa.

[0048] According to one aspect, a vehicle is provided comprising a transmission unit as described in this document. In particular, a bicycle is provided comprising a transmission unit as described in this document. The bicycle comprises, for example, a hub assembly and / or a crank assembly incorporating a continuously variable transmission unit as described in this document.

[0049] According to one aspect, a gearless transmission unit is provided, such as for a bicycle, that provides at least two discrete selectable gear ratios, wherein a first of the at least two gear ratios is provided by a first endless drive member and wherein a second of the at least two gear ratios is provided by a second endless drive member.

[0050] Optionally, the first and second endless drive elements are placed in parallel between an input and an output of the gearless transmission unit, and the gearless transmission unit includes a selector for selecting power transmission via the first or second endless drive element.

[0051] Optionally, the gearless transmission unit includes a clutch for selecting power transmission via the first endless drive element or the second endless drive element.

[0052] Optionally, the gearless transmission unit further includes a third endless drive element and a fourth endless drive element, the third and fourth endless drive elements being placed in parallel between an output of the first and second endless drive elements and an output of the gearless transmission unit, and the gearless transmission unit includes a selector for selecting power transmission via the third or fourth endless drive element.

[0053] Optionally, the gearless transmission unit includes a clutch for selecting power transmission via the third endless drive element or the fourth endless drive element.

[0054] Optionally, the clutch is designed to be engaged and / or disengaged under load. The clutch is, for example, a powershift clutch.

[0055] Optionally, at least one of the first, second, third, and fourth endless drive elements is unlubricated. In particular, each endless drive element of the gearless transmission unit may be unlubricated. Therefore, no lubricating fluid is provided to at least one of the first endless drive element, the second endless drive element, the third endless drive element, and the fourth endless drive element, in particular to all four of the endless drive elements. A dry drive system can therefore be achieved.

[0056] Optionally, for example, at least one of the first, second, third, and fourth endless drive elements comprises a dry belt or a dry chain.

[0057] Optionally, at least one of the first, second, third, and fourth endless drive elements comprises a lubricated chain. In particular, and as an alternative to a dry drive system, each endless drive element of the gearless transmission unit may be lubricated, e.g., with a lubricating fluid such as oil.

[0058] Optionally, the gearless transmission unit includes a continuously variable transmission, e.g., a continuously variable transmission as described in this document.

[0059] In one aspect, each of the gear ratios provided by the transmission system described in this document is oil-free, preferably lubrication-free.

[0060] According to one aspect, a hub assembly for a bicycle is provided that includes the gearless transmission unit.

[0061] According to one aspect, a crank assembly for a bicycle is provided that includes the gearless transmission unit.

[0062] According to one aspect, a distributed transmission system for a bicycle is provided, comprising a crank transmission including the CVT as described herein, and optionally the first transmission as described herein, and a hub transmission including the second transmission as described herein. It is understood that, alternatively, the crank transmission may include the second transmission as described herein, and the hub transmission may include the first transmission as described herein.

[0063] According to one aspect, an electrically powered vehicle is provided, such as a lightweight electrically powered vehicle, for example, an electrically powered bicycle or an electrically powered scooter. The electrically powered vehicle comprises an electric drive motor having an output power of a maximum of 10 kW, preferably a maximum of 4 kW; wherein the electric drive motor is arranged to drive a driven wheel of the vehicle, wherein a continuously variable transmission unit, as described herein, is arranged in a transmission path between the electric drive motor and the driven wheel.

[0064] According to one aspect, a continuously variable transmission unit as described in this document is arranged in a transmission path towards a driven wheel of a vehicle without an internal combustion engine.

[0065] It is understood that one or more of the above aspects, features, and options may be combined. It is understood that any of the options described with respect to one aspect may also be applied to any of the other aspects. It is also clear that all aspects, features, and options described with respect to the transmission unit also apply to the hub and crank assembly. SHORT DESCRIPTION OF THE DRAWING

[0066] The invention will be explained in more detail based on exemplary embodiments illustrated in a drawing. The exemplary embodiments are for illustrative purposes and are not exhaustive. It should be noted that the figures are only schematic representations of embodiments of the invention, which serve as examples and are not limiting.

[0067] The drawing shows: Fig. 1A-1D a schematic example of a continuously variable transmission unit; Fig. 2 is a perspective view of an exemplary continuously variable transmission unit; Fig. 3A-3C are perspective views of exemplary components of a continuously variable transmission unit; Fig. 4A-4D are cross-sectional views of an exemplary continuously variable transmission unit; Fig. 5A-5B are perspective views of exemplary components of a continuously variable transmission unit; Fig. 6A-6C are cross-sectional views of an exemplary continuously variable transmission unit; Fig. 7A-7B are perspective views of exemplary components of a continuously variable transmission unit; Fig. 8A-8C are cross-sectional views of an exemplary continuously variable transmission unit; Fig. 9A-9B illustrate a schematic layout of a transmission system including an exemplary continuously variable transmission unit; Fig. 10A-10B illustrate a schematic layout of a transmission system including an exemplary continuously variable transmission unit; Fig. 11 shows a schematic structure of a transmission system including an exemplary continuously variable transmission unit; Fig. 12A-13B show a schematic structure of a transmission system including an exemplary continuously variable transmission unit; Fig. 13 shows a schematic example of a transmission system comprising a continuously variable transmission unit; Fig. 14A-14B illustrate a schematic layout of a transmission system including an exemplary continuously variable transmission unit; Fig. 15 is a schematic diagram of a transmission system including an exemplary continuously variable transmission unit; Fig. 16 is a schematic diagram of a transmission system including an exemplary continuously variable transmission unit; Fig. 17 shows a schematic structure of a transmission system including an exemplary continuously variable transmission unit; Fig. 18A-18B illustrate a schematic layout of a transmission system including an exemplary continuously variable transmission unit; Fig. 19A-19B is a schematic diagram of a transmission system including a continuously variable transmission unit; Fig. 20 is a schematic diagram of a transmission system including an exemplary continuously variable transmission unit; Fig. 21A-21B is a diagram of a transmission system including a continuously variable transmission unit; Fig. 22A-22B are schematic examples of a transmission system including a continuously variable transmission unit; Fig. 23A-23B is a schematic diagram of a transmission system including a continuously variable transmission unit; Fig. 24A-24B is a schematic diagram of a transmission system including a continuously variable transmission unit; Fig. 25A-25B are perspective and cross-sectional views of exemplary components of a continuously variable transmission unit; and Fig. 26A-26B Examples of a bicycle. DETAILED DESCRIPTION

[0068] Fig. 1A and Fig. 1B shows a schematic example of a continuously variable transmission (CVT) unit 403, in particular of the ratchet type. The CVT unit 403 includes a first drive element 410, which here forms an input of the CVT unit 403, and a second drive element 420, which here forms an output of the CVT unit 403. The first drive element 410 is rotatable about a first axis 407. The second drive element 420 is rotatable about a second axis 406 parallel to the first axis 407. Torque can be transmitted from the first drive element 410 to the second drive element 420 by means of first coupling elements 411. The first coupling elements 411, in this example four first coupling elements, are arranged concentrically with respect to the first axis 407 at a constant first radius R1 from the first axis 407.The first drive element 410 and the second drive element 420 are movable, e.g., displaceable, relative to each other in a direction transverse to the first and second axes 407, 406, e.g., to provide an offset between the first axis 407 and the second axis 406. Torque can be transmitted from the first drive element 410 to the second drive element 420 by means of the first coupling elements 411 at a variable second radius R2 from the second axis 406. Therefore, torque can be transmitted from the constant first radius R1 to the variable second radius R2. Therefore, different ratios between the first radius R1 and the second radius R2 can be achieved, resulting in different gear ratios between the first drive element 410 and the second drive element 420.

[0069] The first coupling elements 411 are movable in a tangential direction relative to the first drive element 410. In this example, the first drive element 410 comprises a first concentric guide 412 that extends concentrically around the first axis 407 at the first radius R1. A tangential movement of the first coupling elements 411 around the first axis 407 is guided by the concentric guide 412. The concentric guide 412 prevents a radial movement of the first coupling elements 411 relative to the first axis 407 in order to keep the first coupling elements 411 at the constant first radius R1 from the first axis 407. The first coupling elements are thus radially coupled to the first drive element 410 relative to the first axis 407.

[0070] With respect to the first axis 407, the first coupling elements 411 can be coupled tangentially to the first drive element 410. For this purpose, in this example, the first coupling elements 411 and the first concentric guide 412 form or include a one-way coupling. The one-way coupling is arranged to enable a tangential movement of the first coupling elements 411 relative to the first concentric guide 412 in one direction and to block a tangential movement of the first coupling elements 411 relative to the first concentric guide 412 in the other, opposite direction. Therefore, the first drive element 410 can drive the first coupling elements 411 in rotation about the first axis 407 in one direction, while allowing the first coupling elements 411 to run freely relative to the first drive element 410 in the other direction.

[0071] The first coupling elements 411 are further movable relative to the second drive element 420 in a radial direction with respect to the second axis 406. In a tangential direction relative to the second axis 406, the first coupling elements 411 are coupled to the second drive element 420. The second drive element 420 comprises, in particular, radial guides 413, e.g., radial slots, extending radially with respect to the second axis 406. Here, the radial guides 413 are evenly and angularly spaced from one another. The first coupling elements 411 are guided in the radial direction with respect to the second axis 406 by the radial guides 413.

[0072] In this example, the CVT unit 403 includes four first coupling elements 411 associated with four respective radial guides 413, but it is understood that the CVT unit 403 may include more than four radial guides 413, e.g., 5, 6, 7, 8, 12, 16. Likewise, the CVT unit 403 may include more than four first coupling elements 411, e.g., 5, 6, 7, 8, 12, 16.

[0073] By moving the first drive element 410 relative to the second drive elements 420 in a direction perpendicular to the first and second axes 407, 406, a distance between the first axis 407 and the second axis 406 can be varied. Therefore, a radius in which torque is transmitted can be varied.

[0074] In the example from Fig. 1A and Fig. 1B, torque is transmitted from the first drive element 410 to the second drive element 420. Fig. 1A and Fig. 1B shows two relative angular positions of the first drive element 410 and the second drive element 420 with the same offset between the first axis 407 and the second axis 406. If the first drive element 410 is driven in a rotational direction about the first axis 407 (e.g., counterclockwise in this example), the first coupling elements 411 are entrained in the rotation of the first drive element 410, and therefore torque can be transferred from the first drive element 410 to the second drive element 420. If the first drive element 410 is driven in the drive direction, all first coupling elements 411 are forced to move with the first drive element 410 at a peripheral speed that is at least equal to a peripheral speed of the first concentric guide 412.If the first drive element 410 is driven in the drive direction, at least some of the first coupling elements 411 can move at a peripheral speed higher than the peripheral speed of the first concentric guide 412. If the first drive element 410 is driven in a non-drive direction about the first axis 407 opposite to the drive direction (e.g., clockwise in this example), freewheeling of the first coupling elements 411 is permitted, and therefore no torque is transmitted from the first drive element 410 to the second drive element 420. In the drive direction of the first drive element 410, at least one of the first coupling elements 411 transmits torque to the first drive element 410 by tangential coupling.

[0075] In particular, at a time, only one of the first coupling elements 411 transmits torque from the first drive element 410 to the second drive element 420 by tangentially coupling it to the first drive element 410. Only one of the first coupling elements 411 is radially coupled to the first drive element 410 by means of the concentric guide 412 and is tangentially coupled to the second drive element 420 by means of the radial guides 413. The coupling element of the first coupling elements 411 that is located at a smallest second radius from the second axis 406 transmits torque. This coupling element is tangentially coupled to the first drive element 410, in particular by means of the one-way coupling of the first coupling element 411 and the concentric guide 412. The coupling element that transmits torque has the lowest tangential speed of the first coupling elements 411.The other coupling elements are located at a larger second radius R2 from the second axis 406 and therefore have a greater tangential speed, are overtaken by the concentric guide 412 in the tangential direction and therefore do not transmit any torque.

[0076] The second radius R2 from the second axis 406, in which torque is transmitted, can be varied by the offset of the first and second axes 407, 406.

[0077] Fig. Figure 1B shows a situation where the smallest second radius R2 is identical for the first coupling elements 411A and 411B. This situation represents the transition point where the first coupling element 411A just begins to transmit torque and the first coupling element 411B just stops transmitting torque.

[0078] Fig. 2 shows an example of a continuously variable transmission unit (CVT unit) 403. The CVT unit 403 of the example from Fig. 2 includes a first drive element 410 and a second drive element 420, and further includes a third drive element 430. Torque can be transferred between the first drive element 410 and the second drive element 420, and between the second drive element 420 and the third drive element 430. The third drive element 430 is similar to the first drive element 410.

[0079] The CVT unit 403 includes first coupling elements 411 for coupling the first drive element 410 to the second drive element 420 and second coupling elements 421 for coupling the second drive element 420 to the third drive element 430.

[0080] The second drive element 420 comprises a first body 420A, which is assigned the first radial guides 413 for interacting with the first coupling elements 411, and a second body 420B, which is assigned second radial guides 423 for interacting with the second coupling elements 421. The first body 420A and the second body 420B are fixedly coupled to one another and rotatable about the second axis 406.

[0081] In this example, the first drive element 410 and the third drive element 430 are both rotatable about the first axis 407. The first drive element 410 includes a first concentric guide 412 for cooperating with the first coupling elements 411, and the third drive element 430 includes a second concentric guide 422 for cooperating with the second coupling elements 421. When driven in the drive direction, the first drive element 410 drives the second drive element 420 via the first coupling elements 411, and the second drive element 420 drives the third drive element 430 via the second coupling elements.

[0082] If the first drive element 410 is driven in the drive direction, all first coupling elements 411 are forced to move with the first drive element 410 at a peripheral speed that is at least equal to a peripheral speed of the first concentric guide 412. If the first drive element 410 is driven in the drive direction, at least some of the first coupling elements 411 can move at a peripheral speed that is higher than the peripheral speed of the first concentric guide 412. The first coupling element 411 of the first coupling elements 411, which is located at a smallest second radius R2 from the second axis 406, transmits torque. The first coupling element 411 that transmits torque has the lowest peripheral speed of the first coupling elements 411.Therefore, the second drive element 420 is driven in rotation in the drive direction by the first coupling elements 411.

[0083] Fig. 1C and Fig. 1D schematically show the second drive element 420 and the third drive element 430.

[0084] If the second drive element 420 is driven in the drive direction, the third drive element 430 is forced to move with the second coupling elements 421 at a peripheral speed equal to a peripheral speed of the fastest second coupling element 421. If the second drive element 420 is driven in the drive direction, at least some of the second coupling elements 421 can move at a peripheral speed lower than the peripheral speed of the second concentric guide 422. The second coupling element 421 of the second coupling elements 421, which is located at a largest second radius R2 from the second axis 406, transmits torque. The second coupling element 421 that transmits torque has the highest peripheral speed of the second coupling elements 421. Fig. Figure 1D shows a situation where the largest second radius R2 is identical for the second coupling elements 421A and 421B. This situation represents the transition point where the second coupling element 421A is just beginning to transmit torque and the second coupling element 421B is just ceasing to transmit torque.

[0085] It is understood that the transmission ratio from the first drive element 410 to the second drive element 420 depends on the ratio of the radii R1 and R2. For each first coupling element 411, the second radius R2 from the second axis 406 will decrease slightly and increase again between the transfer points (411A, 411B). Therefore, the transmission ratio will also increase and decrease slightly. Likewise, the transmission ratio from the second drive element to the third drive element depends on the ratio of the radii R1 and R2. For each second coupling element 421, the second radius R2 from the second axis 406 will decrease slightly and increase again between the transfer points (421A, 421B). To minimize this effect, the first radial guides 413 can be positioned angularly offset relative to the second radial guides 423. The first radial guides 413 can, for example,be positioned angularly halfway between two second radial guides 423. This is shown, for example, in . Fig. 2 can be seen.

[0086] A first continuously variable transmission gear ratio can be obtained between the first input element 410, which can be an input of the CVT unit 403, and the second input element 420. A second continuously variable transmission gear ratio can be obtained between the second input element 420 and the third input element 430, which can be an output of the CVT unit 403. Accordingly, a continuously variable transmission gear ratio of the CVT unit 403 between the first input element 410 and the third input element 430 can be obtained, which is a product of the first and second gear ratios. Therefore, a resulting range of gear ratios of the CVT unit 403, including the first, second, and third input elements, is larger than a range of the first or second gear ratios.In particular, the first and second gear ratios may be the same.

[0087] In this specific example, the CVT unit 403 has five first coupling elements 411 and five second coupling elements 421, which are assigned to five first radial guides 413 and five second radial guides 423, respectively. Here, all of the first coupling elements 411, 421 are the same. However, the orientation of the first and second coupling elements is opposite. This is because the first coupling elements 411 are intended to transmit torque when driven by the first input element 410, and the second coupling elements 421 are intended to transmit torque when driven by the third input element 430. The first radial guides 413 and, likewise, the second radial guides 423 are evenly and angularly spaced from each other. Here, the first radial guides 413 are in antiphase with respect to the second radial guides 423.In this specific example, the first radial guides 413 are angularly displaced by 36 degrees around the second axis 406 with respect to the second radial guides 423.

[0088] The CVT unit 403 is programmable to operate at any gear ratio within a CVT gear ratio range. In this example, the CVT unit 403 is operable at any gear ratio within a range of 1 to approximately 1.5, e.g., 1 to 1.5. However, other ranges are contemplated, e.g., 1 to 2. The CVT unit 403 can be controlled to selectively operate at one of two, three, four, five, or more different gear ratios within the range.

[0089] Fig. 3A shows an example of a coupling element 411, 421 of the first and second coupling elements 411, 421. The coupling element 411, 421 is arranged such that it is allowed to move relative to the first or second concentric guide 412, 422 in a free-running direction, and is coupled to the first or second concentric guide 412, 422 when driven in the opposite direction. In the example, the coupling element 411, 421 comprises a coupling body, here a wedging body, in this case two coupling bodies, here two wedging bodies 11, 12. In the example (see Fig. 2) each first coupling element 411 comprises a first coupling body, here a first wedging body 11A, and a second coupling body, here a second wedging body 12A. In the example (see Fig. 2) Each second coupling element comprises a third coupling body, here a third wedging body 12B, and a fourth coupling body, here a fourth wedging body 11B. Here, the two wedging bodies 11, 12 can be in a neutral state, in which free movement of the coupling element 411, 421 relative to the first or second concentric guide 412, 422 is enabled, and a coupled state, here wedged state, in which the wedging bodies 11, 11A, 11B, 12, 12A, 12B are wedged between two concentric circumferential walls of the first or second concentric guide 412, 422, for coupling the coupling element 411, 421 to the first or second concentric guide 412, 422.

[0090] In the example, the first concentric guide 412 includes a first guide portion 412A on a first side of the first body 420A of the second drive member 420 and a second guide portion 412B on an opposite second side of the first body 420A of the second drive member 420. In this example, the second concentric guide 422 includes a third guide portion 422A on a first side of the second body 420B of the second drive member 420 and a fourth guide portion 422B on an opposite second side of the second body 420B of the second drive member 420.

[0091] Here, the first coupling elements 411 are coupled to the second drive element 420 in a tangential direction and are movable relative to the second drive element 420 in a radial direction. The first and second coupling bodies 11A, 12A are coupled to the first and second guide parts 412A, 412B in a radial direction at a constant radius from the first axis 407 and are movable relative to the first and second guide parts 412A, 412B in the first tangential direction. The first and second coupling bodies 11A, 12A are coupled to the first and second guide parts 412A, 412B in the second tangential direction opposite to the first tangential direction. Therefore, the first drive element 410 can drive the second drive element 420 in rotation in the first tangential direction and the first drive element 410 can move freely in the second tangential direction relative to the second drive element 420.Here, the second coupling elements 421 are coupled to the second drive element 420 in a tangential direction and are movable relative to the second drive element 420 in a radial direction. The third and fourth coupling bodies 12B, 11B are coupled to the third and fourth guide parts 422A, 422B in a radial direction at a constant radius from the third axis and are movable relative to the third and fourth guide parts 422A, 422B in the second tangential direction. The third and fourth coupling bodies 12B, 11B are coupled to the third and fourth guide parts 422A, 422B in the first tangential direction. Therefore, the second drive element 420 can drive the third drive element 430 in rotation in the first tangential direction and the second drive element 420 can move freely in the second tangential direction relative to the third drive element 430.

[0092] Each wedging body 11, 11A, 11B, 12, 12A, 12B is assigned to at least one roller, in this example two rollers 16, 17, 18, 19, for activating the wedging of the wedging body 11, 11A, 11B, 12, 12A, 12B from the neutral state to the wedged state. Each wedging body 11, 11A, 11B, 12, 12A, 12B includes a converging wedging recess 20, 22 for receiving a first of the rollers 16, 18 and a diverging wedging recess 21, 23 for receiving a second of the other rollers 17, 19. Here, converging and diverging are defined as viewed in a direction away from the axis 13 of the wedging body.With respect to the freewheeling direction of the coupling element 411, 421, the converging wedging recess 20, 22 is arranged on a front side of each wedging body 11, 11A, 11B, 12, 12A, 12B, and the diverging wedging recess 21, 23 is arranged on a rear side of the wedging body 11, 11A, 11B, 12, 12A, 12B. Here, the converging wedging recess 20, 22 is arranged to run along a radially inner circumferential wall of the first or second concentric guide 412, 422, and the diverging wedging edge 21, 23 is arranged to run along a radially outer circumferential wall of the first or second concentric guide 412, 422.

[0093] The wedging recesses 20-23 are configured to cooperate with their respective rollers 16-19 such that each wedging body 11, 11A, 11B, 12, 12A, 12B is brought from the neutral state to the wedged state when the coupling element 411, 421 is driven in a direction opposite to the freewheeling direction.

[0094] Fig. 3B shows an example of the second drive element 420, which here comprises the first body 420A and the second body 420B, which are rigidly coupled to each other by means of a connecting shaft 400.

[0095] Fig. 3C shows an assembly in which a coupling element 411, 421, as in Fig. 3A, is provided in each of the radial guides 413, 423 of the second drive element 420, as shown in Fig. 3B shown.

[0096] Fig. 4A-4D show cross-sectional views of an example of the CVT unit 403. Fig. 4A and Fig. 4B show a first state of the CVT unit 403 in which the first axis 407 and the second axis 406 coincide. Fig. 4C and Fig. 4D show a second state of the CVT unit 403 in which the second axis 406 is offset from the first axis 407. The CVT unit 403 is movable between at least the first and second states. Fig. 4A and Fig. 4C show in particular a relative positioning between the first drive element 410 and the second drive element 420 and Fig. 4B and Fig. 4D show a relative positioning between the second drive element 420 and the third drive element 430. Here, the second axis 406 is supported by an axis support 425. The axis support 425 is pivotable about a pivot axis 426. An actuator may be provided for pivoting the axis support to adjust an offset distance between the first axis 407 and the second axis 406. Alternatively or additionally, a linear guide may be provided for supporting the second axis 406. An actuator may be provided for moving the linear guide to adjust an offset distance between the first axis 407 and the second axis 406.

[0097] In the first state, the CVT unit 403 operates according to a first gear ratio, here a 1:1 ratio, and in the second state, the CVT unit 403 operates, for example, according to the second gear ratio, which is different from the first gear ratio. It is understood that the CVT unit 403 may include additional states for operating the CVT unit 403 according to additional gear ratios, e.g., a third and a fourth gear ratio, etc.

[0098] In the first state of the CVT unit 403, torque is transmitted from the first input member 410 at a constant first radius from the first axle 407 to the second input member 420 at a variable second radius from the second axle 406, where the first radius and the second radius are the same. In this case, all of the first coupling elements 411 can transmit torque. Torque is also transmitted from the second input member 420 at a constant third radius from the first axle 407 to the third input member 430 at a variable fourth radius from the second axle 406, where the third radius and the fourth radius are the same. In this case, all of the second coupling elements 421 can transmit torque.In the second state of the CVT unit 403, where the first axis 407 and the second axis 406 are positioned eccentrically relative to each other, torque is transferred from the first input member 410 at the constant first radius from the first axis 407 to the second input member 420 at the variable second radius from the second axis 406, where the first radius and the second radius are different. Torque is also transferred from the second input member 420 at the constant third radius from the first axis 407 to the third input member 430 at the variable fourth radius from the second axis 406, where the third radius and the fourth radius are different. In this specific example, the first and third radii are the same, and the second and fourth radii are the same.

[0099] The CVT unit 403 is operable within a range of gear ratios, for example, from a 1:1 gear ratio to a 1:1.5 gear ratio, with any gear ratio within this range being selectable. To increase the range of gear ratios for a vehicle, such as a bicycle, the CVT unit 403 may be used in conjunction with another transmission. In particular, the CVT unit 304 may be connected in series with another transmission. The another transmission may, for example, be operable according to a finite set of gear ratios, with the steps between the gear ratios of the another transmission being relatively large. The CVT unit 304 may accordingly provide intermediate gear ratios between the large ratio steps of the another transmission.

[0100] Fig. 5A, Fig. 5B, Fig. 6A, Fig. 6B, Fig. 6C show an example of a CVT unit 403 that differs somewhat from the one shown in Fig. 2-4D, but also shows similarities. In this example, each first coupling element 411 comprises a first coupling body, here a first wedging body 11A, and a second coupling body, here a second wedging body 12A. Here, each wedging body 11A, 12A is associated with a single roller 16, 18 for moving the wedging body 11A, 12A from the neutral state to the wedged state. Here, the wedging bodies 11A, 12A can be wedged between two circumferential walls of the first concentric guide, in particular between a radially inner circumferential wall 412A2, 412B2 and a radially outer circumferential wall 421A1, 412B1. In this example, the first and second wedging bodies 11A, 12A are mutually connected at a bridge portion 411B. Here, the first and second wedging bodies 11A, 12A and the bridge portion 411B form a unitary part.In this example, the first coupling element 411 is assigned a support block 411C for supporting the first radial guides 413, 413A, 413B. Here, the first radial guides 413 include first radial guides of a first type 413A and first radial guides of a second type 413B. The radial guides of the first type 413A are, in this example, stronger than the radial guides of the second type 413B. The support block 411C supports itself on the first radial guides of the first type 413A when transmitting torque. The support block 411C enables the first coupling element 411 to move radially inward and outward along the first radial guide 413A while the support block slides and / or tilts along the first radial guide. Here, the support block 411C has a rounded support surface 411C1 for abutting the first radial guide 413A.The rounded support surface 411C1 has a radius of curvature around an axis parallel to the first axis 407. The radius of curvature can be, for example, 10-90 mm, such as 30-60 mm, e.g., 40-50 mm. The relatively large radius enables a relatively large torque transmission. The rounded support surface facilitates sliding and / or tilting of the first coupling element. The support block 411C rests against the first coupling element 411, here against the bridge section 411B. The support block 411C is pivotable relative to the first coupling element 411. Here, the first coupling element 411, in particular the bridge portion 411B, comprises a rounded surface 411B1 for abutting against the support block 411C to enable pivoting of the support block 411C relative to the first coupling element 411. The rounded surface 411B1 has a radius of curvature about an axis that is parallel to the first axis 407. The radius of curvature of the rounded surface 411B1 can be, for example,10-90 mm, such as 30-60 mm, e.g. 40-50 mm. Additionally or alternatively, the support block 411C may have a second rounded surface for abutting the first coupling element 411, in particular the bridge portion 411B. The first coupling element 411 may include provisions, such as one or more projections, for holding the support block in place. Alternatively or additionally, the support block 411C may include provisions, such as one or more projections, for holding the support block in place relative to the first coupling element. In this example, the support block 411C is flexibly pivotally attached to the coupling element 411, here with a compliant pin 411E. Therefore, the support block can dissipate some misalignment between the wedging bodies and the support block and allow the support block to pivot relative to the first coupling element, e.g. B. while changing the gear ratio.A pivoting range of the support block relative to the first coupling element can be, for example, 15 degrees, such as 10 degrees, such as 5 degrees. Since torque is continuously transmitted using successive coupling elements during use of the CVT, the radius in which torque is transmitted is transferred from one coupling element to the next, so a relatively smaller pivoting range per support block can still be sufficient for a larger change in the gear ratio.

[0101] In this example, the first radial guides 413A comprise a radially extending projection 413C, here a guide rib, and the first coupling elements 411 comprise a recess 411D, here a guide slot, configured to cooperate with the projection 413C for axially aligning the first coupling elements 411 with the second drive element 420. In this example, the recess 411D is provided in the support block 411C.

[0102] Fig. 7A, Fig. 7B, Fig. 8A, Fig. 8B, Fig. 8C show an example of a CVT unit 403 that differs somewhat from the one shown in Fig. 2-6B, but also shows similarities. In this example, each first coupling element 411 comprises a first coupling body, here a first wedging body 11A, and a second coupling body, here a second wedging body 12A. Here, each wedging body 11A, 12A is associated with a single roller 16, 18 for moving the wedging body 11A, 12A from the neutral state to the wedged state. Here, the wedging bodies 11A, 12A are arranged to clamp a radially inner and outer surface of a circumferential wall 412C of the first guide part 410. In this example, the first and second wedging bodies 11A, 12A are mutually connected at a bridge portion 411B. Here, the first and second wedging bodies 11A, 12A and the bridge section 411B form a unitary part.In this example, the first coupling element 411 is assigned a support block 411C for supporting the first radial guides 413, 413A, 413B. Here, the first radial guides 413 include first radial guides of a first type 413A and first radial guides of a second type 413B. The radial guides of the first type 413A are, in this example, stronger than the radial guides of the second type 413B. The support block 411C supports itself on the first radial guides of the first type 413A when transmitting torque. The support block 411C enables the first coupling element 411 to move radially inward and outward along the first radial guide 413A while the support block slides and / or tilts along the first radial guide. Here, the support block 411C has a rounded support surface 411C for abutting the first radial guide 413A.The rounded support surface 411C1 has a radius of curvature around an axis parallel to the first axis 407. The radius of curvature can be, for example, 10-90 mm, such as 30-60 mm, e.g., 40-50 mm. The relatively large radius enables a relatively large torque transmission. The rounded support surface facilitates sliding and / or tilting of the first coupling element. The support block 411C rests against the first coupling element 411, here against the bridge section 411B. The support block 411C is pivotable relative to the first coupling element 411. Here, the first coupling element 411, in particular the bridge portion 411B, comprises a rounded surface 411B1 for abutting against the support block 411C to enable pivoting of the support block 411C relative to the first coupling element 411. The rounded surface 411B1 has a radius of curvature about an axis that is parallel to the first axis 407. The radius of curvature of the rounded surface 411B1 can be, for example,10-90 mm, such as 30-60 mm, e.g. 40-50 mm. Additionally or alternatively, the support block 411C may have a second rounded surface for abutting the first coupling element 411, in particular the bridge portion 411B. The first coupling element 411 may include provisions, such as one or more projections, for holding the support block in place. Alternatively or additionally, the support block 411C may include provisions, such as one or more projections, for holding the support block in place relative to the first coupling element. In this example, the support block 411C is flexibly pivotally attached to the coupling element 411, here with a compliant pin 411E. Therefore, the support block can dissipate some misalignment between the wedging bodies and the support block and allow the support block to pivot relative to the first coupling element, e.g. B. while changing the gear ratio.A pivoting range of the support block relative to the first coupling element can be, for example, 15 degrees, such as 10 degrees, such as 5 degrees. Since torque is continuously transmitted using successive coupling elements during use of the CVT, the radius in which torque is transmitted is transferred from one coupling element to the next, so a relatively smaller pivoting range per support block can still be sufficient for a larger change in the gear ratio.

[0103] In this example, the first radial guides 413A comprise a radially extending projection 413C, here a guide rib, and the first coupling elements 411 comprise a recess 411D, here a guide slot, configured to cooperate with the projection 413C for axially aligning the first coupling elements 411 with the second drive element 420. In this example, the recess 411D is provided in the support block 411C.

[0104] It is understood that the CVT unit 403 is made of Fig. 5A-6C or 7A-8C also in a Fig. 2, wherein a third drive element 430 is used. The third drive element 430 may be the same or substantially the same as the first drive element 410. It is also possible to provide a CVT unit 403 having a first stage according to the first drive element and the second drive element 420 (in particular, first body 420A), as described with regard to Fig. 2-4D, and a second stage according to Fig. 5A-6C or 7A-8D; or which has a first stage according to Fig. 5A-6C or 7A-8C and a second stage according to the third drive element and the second drive element 420 (in particular second body 420B), as with regard to Fig. 2-4D. If a CVT unit is (partially) referred to in the following Fig. 2-4D, a CVT unit according to 5A-6C or 7A-8C or a combination thereof may also be used.

[0105] Fig. 9A and Fig. 9B show an example of a transmission system in which the CVT unit 304 is connected in series with another transmission operable according to at least two other gear ratios. Fig. 9A and Fig. 9B in particular show a schematic structure of a hub assembly 1 comprising a CVT unit 304. In this example, the CVT unit 304 is arranged coaxially with respect to a wheel axle 480, in particular a rear wheel axle of a bicycle. The hub assembly 1 comprises a hub shell 485 in which the CVT unit 304 is provided. The hub shell 485 is connected to an output, here a driven (rear) wheel of a bicycle. The hub assembly also comprises a driver 490 for receiving one or more sprockets, such as a cassette that includes more than one sprocket, in this example three sprockets 491, 492, 493 of different sizes. The sprockets 491, 492, 493 are rotatably fixed to the driver 490 and are arranged to be driven by a chain or a belt. The driver 490 is connectable to an input of the CVT unit 403 for transmitting torque, e.g., via a one-way bearing 427.The driver 490 can in particular be coupled to the first drive element 410 of the CVT unit 403.

[0106] The first drive element 410 of the CVT unit 403 is rotatable about the axis 480, with the first axis 407 coinciding with a centerline of the axis 480. The second drive element 420 is rotatable about a bushing 428. The second axis 406 coincides with a centerline of the bushing 428. The bushing 428 is movable in a transverse direction, transverse to the first axis 407, to change a gear ratio of the CVT unit 304. The third drive element 430 forms an output of the CVT unit 403 and, in this example, is fixed to the hub shell 485.

[0107] Fig. 9A shows the hub assembly 1, with the CVT unit 403 in a first state in which the first and second axles 407, 406 coincide. Therefore, in this first state, the CVT unit 403 operates according to a 1:1 gear ratio. Fig. 9B shows the hub assembly 1 with the CVT unit 403 in a second state in which the second axis 406 is offset from the first axis 407. Therefore, in this second state, the CVT unit 403 operates according to a gear ratio other than a 1:1 gear ratio, for example, a 1:1.5 gear ratio. Regardless of the state of the CVT unit 403, any of the ring gears 491, 492, 493 can be selected. In particular, the ring gears 491, 492, 493 can be used to increase the range of available gear ratios. Therefore, a size difference between successive ring gears, and therefore a gear ratio step between the ring gears, can be relatively large compared to conventional ring gear transmissions.

[0108] The CVT unit 403 and the further transmission, which here includes the sprockets 491, 492, 493, can be operated independently, e.g., by dedicated actuators. In this example, the chain can be shifted from one sprocket to the next, e.g., using a conventional derailleur, independently of the lateral displacement of the second drive element 420 of the CVT unit 403.

[0109] Fig. 10A and Fig. 10B show a concrete example of the hub assembly from Fig. 9A and Fig. 9B, wherein the sprockets 491, 492, 493 for shifting the chain from one sprocket to the next are arranged to move axially relative to the driver 490. In this way, the chain can be kept straight at all times for increased efficiency.

[0110] Fig. Figure 11 shows an example of a hub assembly 1, wherein the sprockets 491, 492, 493 are fixedly mounted to an input of the CVT unit 403, here the first drive element 410. A conventional derailleur can be used, for example, to shift the chain between the sprockets.

[0111] Fig. 12A and Fig. 12B shows an example of a hub assembly 1, wherein a sprocket cassette, which here has six sprockets 491, 492, 493, 494, 495, 496, is fixedly mounted on the second drive element 420. The second drive element 420 therefore forms the input of the CVT unit 403 in this example. The sprockets 491-496 and the second drive element 420 are rotatable together about the second axis 406. The CVT unit 403 does not include a third drive element 430 in this example. The first drive element 410 forms the output of the CVT unit 403 and is fixed to the hub shell 485. The first drive element 410 and the hub shell 485 are rotatable together about the first axis 407. Torque is transmitted from any of the gear rings 491-496 via the CVT unit 403 to the hub shell 485. In the Fig. 12A, Fig. In the example shown in Figure 12B, the CVT gear ratio can be changed by moving the second drive member 420 relative to the first drive member 410 in a direction transverse to the first axis 407, here by means of an actuator 380. Therefore, the sprocket cassette 491-496, together with the second drive member 420, can be moved eccentrically with respect to the first axis 407 into a position in which the first and second axes 407, 406 are offset from each other. Fig. 12A shows the hub assembly 1 in a centric state in which the first axis 407 and the second axis 406 coincide, and Fig. Figure 12B shows the hub assembly 1 in an eccentric state in which the first axis 407 and the second axis 406 are offset from each other. The actuator 380 can move the hub assembly between the centric and eccentric states.

[0112] Fig. 13 shows a schematic example of a transmission system 10 comprising a CVT unit 403, a first transmission 100, and a second transmission 200. The first transmission 100 and the second transmission 200 are connected in series, with the CVT unit 403 here connected between the first transmission 100 and the second transmission 200. Fig. 14A and Fig. 14B show a schematic structure of the transmission system 10, as in Fig. 13 shown.

[0113] The transmission system 10 includes an input I and an output O. The input I can be connected, for example, to a crank of the bicycle. The output O can be connected, for example, to a front chainring of the bicycle. Between the input I and the output O, the system includes the first transmission 100, which has two parallel transmission paths 100A, 100B, the CVT unit 403, and the second transmission 200, which has two parallel transmission paths 200A, 200B. A first input 101 of the first transmission 100 is connected to the system input I. A second output 202 of the second transmission 200 is connected to the system output O. A first output 102 of the first transmission 100 is connected to an input 404 of the CVT unit 403. An output 405 of the CVT unit 403 is connected to the second input 201 of the second transmission 200.In this example, the input shaft I and the output shaft O are arranged coaxially with respect to one another, but it is understood that an offset arrangement in which the input shaft and the output shaft are offset with respect to one another can also be provided. It is further understood that the CVT unit 403 and / or the input I and / or the output O can be arranged coaxially. Here, the CVT unit 403, which is associated with a second axis 406, is provided offset from the input and output shafts in order to achieve a specifically compact design.

[0114] Here, the first transmission 100 is operable according to a first gear ratio and a second gear ratio. Similarly, the second transmission 200 is operable according to a third gear ratio and a fourth gear ratio. The first and second transmissions 100, 200 may include respective gears 100A1, 100A2, 100B1, 100B2, 200A1, 200A2, 200B1, 200B2 for providing a reduction or increase in the gear ratio between the first input 101 and the first output 102, or between the second input 201 and the second output 202, respectively.

[0115] The first transmission output 102 and the CVT input 404 are rigidly connected to each other here. Likewise, the CVT output 405 and the second transmission input 201 are also rigidly connected to each other. Here, the gears 100A2 and 100B2 of the first and second transmission paths 100A, 100B, respectively, are integrated into the CVT input 404. The gears 200A1 and 200B1 of the third and fourth transmission paths 200A, 200B, respectively, are integrated into the CVT output 405. The CVT unit 403 is arranged to provide a continuously variable transmission ratio between the CVT input 404 and the CVT output 405.

[0116] To shift between the first gear ratio and the second gear ratio, the first transmission 100 includes a first clutch, in this example, a powershift clutch C1. Similarly, the second transmission 200 includes a second clutch, in this example, a powershift clutch C2, for selectively shifting between the third gear ratio and the fourth gear ratio of the second transmission 200.

[0117] The first transmission 100 has two parallel transmission paths between the first input 101 and the first output 102, namely a first transmission path 100A and a second transmission path 100B. At least one of the first and second transmission paths 100A, 100B includes the first powershift clutch C1. Also, at least one of the parallel transmission paths 100A, 100B includes gear teeth. In this example, the first transmission path 100A includes gears 100A1, 100A2 arranged to provide the first gear ratio, and the second transmission path 100B includes gears 100B1, 100B2 arranged to provide the second gear ratio.

[0118] Likewise, the second transmission 200 has two parallel transmission paths between the second input 201 and the second output 202, namely a third transmission path 200A and a fourth transmission path 200B. At least one of the third and fourth transmission paths 200A, 200B includes the second powershift clutch C2. Also, at least one of the parallel transmission paths 200A, 200B of the second transmission 200 includes gear teeth. In this example, the third transmission path 200A includes gears 200A1, 200A2 arranged to provide the third gear ratio, and the fourth transmission path 200B includes gears 200B1, 200B2 arranged to provide the fourth gear ratio.

[0119] The powershift clutches C1 and C2 can be used to select an appropriate transmission path between the system input I and the system output O. More specifically, the first powershift clutch C1 can be used to selectively switch between the first 100A and the second 100B parallel transmission paths of the first transmission 100, and the second powershift clutch C2 can be used to selectively switch between the third 200A and the fourth 200B parallel transmission paths of the second transmission 200.

[0120] The powershift clutches include at least two states, e.g., a coupled state and an uncoupled state. The coupled state couples the clutch input to the clutch output to transmit torque through the clutch, and the uncoupled state decouples the clutch input from the clutch output to prevent torque from being transmitted through the clutch. In the uncoupled state, the powershift clutches C1, C2 allow torque to be transmitted through another, parallel transmission path.

[0121] In the coupled state of the first powershift clutch C1, torque can be transmitted through the second transmission path 100B from the system input I to the first output 102. In the uncoupled state, torque can be transmitted through the first transmission path 100A from the system input I to the first output 102. Likewise, in the coupled state of the second powershift clutch C2, torque can be transmitted through the fourth transmission path 200B from the second input 201 to the system output O. In the uncoupled state, torque can be transmitted through the third transmission path 200A from the first input 201 to the system output O.

[0122] In this example, the power shift clutches C1, C2 are provided in the first transmission path 100A and the fourth transmission path 200B, respectively, but it is understood that the first power shift clutches C1, C2 may also be provided in the second transmission path 100B and the third transmission path 200A, respectively.

[0123] Here, the first transmission path 100A includes a first one-way clutch V1. The first one-way clutch V1 can be overrun, e.g., when torque is transmitted through the first transmission path 100A, e.g., when the first output 102 rotates faster than the first input 101. Here, the third transmission path 200A includes a second one-way clutch V2. The second one-way clutch V2 can be overrun, e.g., when torque is transmitted through the fourth transmission path 200B, e.g., when the second output 202 rotates faster than the second input 201. The one-way clutches V1, V2 are preferably low-friction when overrunning to reduce losses.

[0124] The powershift clutches C1, C2 are, at least in this example, particularly arranged to be coupled and uncoupled under load, i.e., while torque is being transmitted through the powershift clutch. The powershift clutches C1, C2 are, for example, positive-locking clutches. It is understood that any of the powershift clutches can also be non-positive clutches arranged to transmit torque in at least one rotational direction.

[0125] It is preferred that clutches C1 and C2 are powershift clutches arranged to be coupled and / or uncoupled under load, but it is understood that clutches C1 and C2 need not be powershift clutches. An example of powershift clutches is described in WO2018 / 199757A2, WO2020 / 085911A2, or WO2021 / 080431A1.

[0126] Here, the first transmission 100 and the second transmission 200 each comprise a further clutch. In this example, the first transmission 100 comprises a first further one-way clutch VB1 and the second transmission 200 comprises a second further one-way clutch VB2. The further one-way clutches VB1, VB2 are here connected to the respective inputs of the powershift clutches C1, C2, but it is understood that the further one-way clutches VB1 and VB2 can also be connected to the respective outputs of the powershift clutches C1, C2. It may be preferable to connect the further one-way clutches VB1, VB2 to the respective inputs of the powershift clutches C1, C2 so that the outputs of the powershift clutches C1, C2 can continue to rotate even when no torque is input to their inputs. This can facilitate the coupling and / or decoupling of the powershift clutches C1, C2.The further clutches VB1 and VB2 can in particular be arranged to enable a reverse direction of rotation of the output O, ie opposite to a driving direction of rotation, relative to the input I.

[0127] In this example, the output 102 of the first transmission 100 is connected to an input 404 of the CVT unit 403. An output 405 of the CVT unit 403 is connected to the input 201 of the second transmission 200. The CVT unit 403 is arranged to provide a gear ratio between the CVT input 404 and the CVT output 405. The input 404 and the output 405 of the CVT are rotatable relative to each other, wherein the CVT unit 403 may be operable, for example, according to at least a fifth gear ratio and a sixth gear ratio and additionally a seventh gear ratio, etc., between the input 404 and the output 405. In this example, the CVT unit 403 is similar to the one shown in Fig. 1-7B shown.

[0128] The CVT unit 403 is assigned to an intermediate axis of the transmission system 10. The intermediate axis is defined here by the first axis 407 of the CVT unit 403, which extends parallel to the input axis of the transmission system 10.

[0129] Fig. 14A shows a first state of the CVT unit 403 in which the second axis 406 and the first axis 407 coincide. Fig. 14B shows a second state of the CVT unit 403 in which the second axle 406 is offset from the first axle 407. The CVT unit 403 is movable between at least the first and second states. In the first state, the CVT unit 403 operates, for example, according to the seventh gear ratio, here a 1:1 ratio, and in the second state, the CVT unit 403 operates, for example, according to the eighth gear ratio, here a 1:1.5 ratio. It is understood that the CVT unit 403 may include additional states for operating the CVT unit 403 according to additional gear ratios, e.g., a ninth gear ratio.

[0130] The transmission system 10 is operable according to various gear ratios, with the CVT unit 403 providing (pre)programmable gear ratios. For example, Table 1 shows an example of system gear ratios that can be achieved by the Fig. 14A, Fig. 14B. The example in Table 1 shows a seven-speed transmission system 10 with a substantially constant gear ratio step size of approximately 1.25.

[0131] In the example from Table 1, each successive shift changes the system gear ratio by approximately 25%. The gear ratios of the CVT unit 403, RCVT, may be preprogrammed. The CVT may be controlled accordingly to shift from one preprogrammed gear ratio to another.

[0132] Table 2 shows another example of system gear ratios achieved by a Fig. 14A, Fig. 14B. This example shows a 10-speed transmission system 1 with a constant gear ratio step size of approximately 1.17. The CVT can be controlled accordingly to switch from one preprogrammed gear ratio to another.

[0133] In the example from Table 2, each successive shift changes the system gear ratio by approximately 17%. The gear ratios of the CVT unit 403 (RCVT) may be preprogrammed.

[0134] Table 3 shows another example of system gear ratios achieved by a Fig. 14A, Fig. 14B. This example shows a 16-speed transmission system 1 with a constant gear ratio step size of approximately 1.10.

[0135] In the example from Table 3, each successive shift changes the system gear ratio by approximately 10%. The gear ratios of the CVT unit 403 (RCVT) may be preprogrammed. The CVT may be controlled accordingly to shift from one preprogrammed gear ratio to another.

[0136] Table 4 shows another example of system gear ratios achieved by a Fig. 14A, Fig. 14B. This example shows a 16-speed transmission system 1 with a constant gear ratio step size of approximately 1.12.

[0137] Table 5 shows another example of system gear ratios achieved by a Fig. 14A, Fig. 14B. This example shows a 21-speed transmission system 1 with a constant gear ratio step size of approximately 1.07.

[0138] Tables 6-8 provide further examples of a set of system gear ratios that can be achieved by a Fig. 14A, Fig. 14B. The gear ratios R1, R2, R3, R4 are the same as for the example in Table 5, but compared to Table 5, Tables 6-8 show a 17-speed, 13-speed, and 9-speed transmission system, respectively, instead of a 21-speed transmission system. The total range of system gear ratios is essentially the same across the examples, as provided by R1-R4, here approximately 400%, but compared to Table 5, the CVTs provide fewer intermediate steps.

[0139] The CVT unit 403 provides intermediate gear ratio steps between the system gear ratios that are only achievable with the first and second transmissions 100, 200. Therefore, the first and second transmissions 100, 200 combined can provide a broadening of the system gear ratios, while the CVT unit 403 can be used to provide convenient intermediate steps between successive system ratios. The CVT unit 403 can also be used to expand the range of system gear ratios provided by the first and second transmissions 100, 200.

[0140] In these examples, the gear ratios are selected in particular such that the number of different CVT gear ratios (RCVT) is smaller than the number of system gear ratios. The number of different CVT gear ratios (RCVT) is in particular smaller than half the number of system gear ratios, and more particularly approximately 25% of the number of system gear ratios.

[0141] The examples from Table 1-8 show a relationship between the system gear ratios that has a substantially constant gear ratio step between successive system gear ratios. It should be understood that any relationship can also be achieved using the CVT unit 403, e.g., progressively increasing and / or decreasing gear ratio steps between successive system gear ratios. The CVT unit 403 can be operated accordingly, e.g., using a control unit. A constant step size between system gear ratios can be considered a linear set of gear ratios. It should be understood that non-linear sets can also be achieved by programming the CVT gear ratios RCVT accordingly. For example, progressively increasing or decreasing gear ratio steps can be achieved.The steps can even be changed spontaneously, i.e. during operation of the transmission, e.g. by properly selecting or reprogramming the CVT RCVT transmission ratios.

[0142] Fig. 15 shows an example of a transmission system 10 corresponding to the Fig. 14A, Fig. 14B, but with the CVT unit 403 arranged between the system input I and the first transmission 100. Therefore, the first drive element 410 is mounted on the input shaft I, and the third drive element 430 is coupled to the input 101 of the first transmission 100. The CVT unit 403 is assigned to the input shaft here.

[0143] The first drive element 410 and the third drive element 430 are arranged coaxially with the input axis. The intermediate axis is defined here by a stationary mounting shaft 401 extending parallel to the input axis.

[0144] The input shaft I can, for example, be attached to a crank of a bicycle. Therefore, the input shaft I can be a crank spindle. The Fig. The transmission shown in Figure 15 can thus be, for example, a crank transmission. The third input element 430, which forms the CVT output, is connected to the first input 101 of the first transmission 100. The CVT unit 403 is arranged to provide a continuously variable transmission ratio, e.g., a set of preprogrammed CVT ratios, between the CVT input and the CVT output formed by the third input element 430. The third input element 430 is connected to the first input 101 of the first transmission 100 and, for this purpose, is provided with the gear 100A1 for meshing with the gear 100A2 to form the first transmission path 100A and the gear 100B1 for meshing with the gear 100B2 to form the second transmission path 100B.

[0145] The CVT unit 403 is arranged coaxially with the input shaft I in this example, i.e., the first axis 407 coincides with the drive axis of the input shaft I. Furthermore, in this example, the connecting shaft 400, which connects the first and second bodies 420A, 420B of the second drive member 420, is arranged radially outside the first and third drive members 410, 430. In other words, the first and third drive bodies 410, 430 are arranged generally radially with respect to the first axis 407 between the first axis 407 and the connecting shaft 400. The connecting shaft 400 can alternatively be arranged radially inside the first and third drive members 410, 430.

[0146] The CVT is configured to apply a CVT gear ratio, e.g., a fifth and a sixth gear ratio, between the first input member 410, which is here rotationally fixed to the input shaft I, and the third input member 430. The first transmission 100 is formed in this example between the third input member 430 and a countershaft 408. The second transmission 200 is formed between the countershaft 408 and the output shaft O. The countershaft 408 is rotatable relative to the stationary mounting shaft 401 in this example. The stationary mounting shaft 401 can, for example, be mounted on a housing 490 of the transmission system 10.

[0147] Fig. 16 shows an example of a transmission system 10 which corresponds to the example from Fig. 14A, Fig. 14B, with an electric motor 450 connected to the third input member 430. In this configuration, torque supplied by the electric motor 450 is not transmitted through the CVT unit 403. The electric motor 450 may be used to propel, or at least assist in propelling, the vehicle. The second transmission 200 is disposed between the electric motor 450 and the system output O. In particular, gears 200A1, 200A2 and gears 200B1, 200B2 are disposed between the electric motor 450 and the system output O, providing two selectable gear ratios between the electric motor and the system output O, for example, a 1:1 and a 2:1 ratio.

[0148] The transmission system 10, in this example, also includes an accelerator gear 460 between the system input I and the input 101 of the first transmission 100. It should be understood that the accelerator gear 460 and the electric motor 450 are independent features. The accelerator gear 460 provides a speed increase from the system input I and the first input 101. Here, the accelerator gear 460 includes a planetary gear set including a carrier 461 coupled to the input shaft, a planetary gear 462 carried by the carrier 461, and a ring gear 463 coupled to the first input 101. The planetary gear 462 meshes with the ring gear 463. A stationary sun gear 464 also meshes with the planetary gear 462, wherein the sun gear 464 is immobile, e.g., relative to a frame of the vehicle, more specifically, a frame of a bicycle.

[0149] In this example, sun gear 464 is connected to a torque sensor 465. Torque sensor 465 is arranged to measure a torque at system input I, e.g., a bicycle crank torque. Such a stationary torque sensor 465 is particularly accurate compared to non-stationary torque sensors.

[0150] Particularly for bicycles, but also for other vehicles, the input torque at system input I can typically be high at a relatively low speed. The acceleration gear 460 thus provides a speed increase as well as a torque reduction between system input I and the first input 101. This reduces loads on the transmission system 1, in particular on the first 100, the second 200 transmission (and any additional transmissions) as well as on the CVT unit 403.

[0151] In the examples, the CVT unit 403 includes the first drive element 410, the second drive element 420, and the third drive element 430. An input of the CVT unit can then be associated with the first drive element 410, and an output of the CVT unit can then be associated with the third drive element 430. This provides the advantage that it is possible for the input and output of the CVT unit to be stationary, with the second axis 406 being movable. It should be understood that it is also possible for the input of the CVT unit to be associated with the first drive element 410 and the output of the CVT unit to be associated with the second drive element 420. In such a case, the third drive element 430 can be omitted.

[0152] Fig. 17 shows an exemplary structure of a transmission system 10 which corresponds to the Fig. 15, wherein an electric motor 450 is provided within the housing 490. Here, the electric motor 450 is connected to the first drive element 410 of the CVT unit 403, here via a reduction gearing. The first drive element 410 is in turn coupled to the input shaft I. Therefore, the electric motor 450 drives the input shaft I in rotation via the first drive element 410. The input shaft I can additionally be driven by an additional power source, such as muscular power of a user transmitted to the input shaft I, e.g., via a crank.

[0153] Fig. 18A and Fig. 18B show respective examples of a transmission system 10, wherein the CVT unit 403 is arranged between the system input I and the first transmission 100. The first input element 410 is mounted on the input shaft I and rotates therewith, and the second input element 420 is coupled to the input 101 of the first transmission 100. The CVT unit 403 does not include a third input element 430 in this example. The first input element 410 forms the input of the CVT unit 403, and the second input element 420 forms the output of the CVT unit 403. Torque is transmitted from the first input element 410 to the second input element 420 via the first coupling elements 411. The first coupling elements 411 engage the first drive element 410 at the constant first radius from the first axis 407 and the second drive element 420 at a variable second radius from the second axis 406.

[0154] Fig. 18A and Fig. 18B show respective configurations of the CVT unit 403. In the example from Fig. 18A, the connecting shaft 400 is arranged radially outside the first drive element 410 and in the example of Fig. 18B, the connecting shaft 400 is arranged radially inside the first drive element 410.

[0155] The second drive element 420 can be moved relative to the first drive element 410 in the radial direction with respect to the first axis 407 in order to offset the second axis 406 from the first axis 407. Similar to the Fig. In the examples shown in Figures 4A-4D, the second drive member 420 is pivotally drivable about a pivot axis 426, wherein the pivot axis 426 is parallel to the first axis 407. In this example, the pivot axis 426 coincides with the intermediate axis of the transmission system 10, wherein the intermediate axis is defined here by the stationary mounting shaft 401. A rigid pivot arm 415, extending between the mounting axis 401 and the connecting shaft 400 of the CVT unit 403, connects the second drive member 420 to the mounting shaft 401. The second drive member 420 is pivotally rotatable at a constant radius from the mounting shaft 401. The constant radius is defined by the pivot arm 415. The primary gears 100A1 and 100B1 of the first transmission 100 are, in this example, mounted on the connecting shaft 400, which in turn is mounted on or integrated into the second drive element 420.The primary gears 100A1 and 100B1 of the first transmission 100 are accordingly also pivotable about the pivot axis 426 together with the CVT output 405. Since the secondary gears 100A2 and 100B2 of the first transmission are rotationally associated with the pivot axis 426, the primary / secondary gear pairs 100A1-100A2 and 100B1-100B2 can remain in meshing engagement while the second drive element 420 is pivoted about the pivot axis 426.

[0156] Fig. 19A, Fig. 19B show a diagram of the pivoting of the second drive element 420 about the pivot axis 426, as with regard to Fig. 18A, Fig. 18B.

[0157] Fig. 20 shows an example of a gearless transmission system 1. The transmission system 10 in this example is similar to that in Fig. 18A, but instead of gear drives for the first and second transmissions 100, 200, the first and second transmissions 100, 200 include belt drives for transmitting torque. In particular, the first transmission 100 includes a first endless drive member 110A disposed in the first transmission path 100A and a second endless drive member 110B disposed in the second transmission path 100B. The first and second endless drive members 110A, 110B, e.g., a first and second belt or chain, respectively connect a first and a second primary gear 100A1, 100B1, e.g., a primary ring gear, to a first and a second secondary gear 100A2, 100B2, e.g., a secondary ring gear.

[0158] In this example, the second transmission 200 likewise includes a third endless drive element 210A disposed in the third transmission path 200A, and a fourth endless drive element 210A disposed in the fourth transmission path 200B. The third and fourth endless drive elements 210A, 210B, e.g., a third and fourth belt or chain, respectively connect a third and fourth primary gear 200A1, 200B1, e.g., a primary ring gear, to a third and fourth secondary gear 200A2, 200B2, e.g., a secondary ring gear. It is understood that any of the gear drives of the transmission systems described herein may also be configured as a belt drive. Similar to the Fig. 19A, Fig. 19B, the second drive element 420 is pivotally rotatable within a constant radius from the mounting shaft 401; the constant radius is defined by the pivot arm 415.

[0159] Fig. 21A, Fig. 21B show a diagram of the pivoting of the second drive element 420 about the pivot axis 426 of the Fig. 20. The primary gears 100A1 and 100B1 of the first transmission 100 are mounted in this example on the connecting shaft 400, which in turn is mounted on or integrated with the second drive element 420. The primary gears 100A1 and 100B1 of the first transmission 100 are accordingly also pivotable about the pivot axis 426 together with the CVT output 405. Since the secondary gears 100A2 and 100B2 of the first transmission are rotationally associated with the pivot axis 426, the primary / secondary gear pairs 100A1-100A2 and 100B1-100B2 remain at a constant distance when the second drive element 420 pivots about the pivot axis 426. Therefore, the primary / secondary gear pairs 100A1-100A2 and 100B1-100B2 can remain engaged by the respective endless drive member 110A, 120B while the second drive member 420 is pivoted about the pivot axis 426.

[0160] For example, when the first drive element 410 is driven in rotation about the first axis 407, the drive force is transmitted through the first coupling elements 411 to the second drive element 420. This tangential force acts on the second drive element 420 in a substantially opposite direction as a reaction force from the endless drive element 110A. Therefore, the pivoting force for pivoting the primary wheel 100A1 together with the second drive element 420 about the pivot axis 426 can be reduced, at least with respect to the Fig. 19A, Fig. 19B shown arrangement with gears.

[0161] It is understood that the scheme consists of Fig. 21A, Fig. 21B also for the exemplary in Fig. 12A, Fig. 12B, in which, instead of the primary gear 100A, a sprocket of the sprocket cassette 491-496 is mounted to rotate together on the second drive member 420 and the hub shell 485 is mounted to the first drive member 410. Instead of the secondary gear 100A2, a front chainring is provided which meshes with the chain 100A and transmits torque via the chain to the sprocket. Therefore, in the example of Fig. 12A, Fig. 12B, the second drive element 420 is located at the input of the CVT unit and the first drive element 410 is located at the output. It is understood that for the hub assembly of Fig. 12A, Fig. 12B, the pivot axis 426 does not have to coincide with the axis of the front chainring. An additional chain tensioner could, for example, be provided to compensate for potential chain slack resulting from relative movement between the first and second drive members 410, 420.

[0162] The Fig. The exemplary gearless transmission system 1 shown in Figure 20 does not include any meshing gears and can therefore be free of oil lubrication. There is no oil bath for lubricating the transmission's rotating elements. Standard bearings, e.g., roller bearings, are used instead. Accordingly, there is no need for oil seals to seal the housing 290 in this example. Instead of lubricating oil, a minimal amount of grease can be applied. The endless drive elements and their associated gears can even be completely lubrication-free.

[0163] Fig. 22A and Fig. 22B show exemplary transmission systems 10, wherein the CVT unit 403 is connected to an input side of the first transmission 100 and wherein the first transmission 100 includes a planetary gear set 50. Here, the CVT 403 is connected in series with the first transmission 100. The planetary gear set is arranged in one of the transmission paths of the first transmission 100, here in the second transmission path 100B. The other transmission path, here the first transmission path 100A, provides a 1:1 gear ratio in this example. The first transmission 100 is connected to the second transmission 200 via an endless drive element 55, e.g., a chain, a belt, or a shaft drive. It is understood that the second transmission 200 and the endless drive element 55 can be omitted. In the exemplary arrangement of Fig. 22A, Fig. 22B, the CVT unit 403 and the first gear can be used as a crank gear, e.g., between a crank and a front chainring of a bicycle, and the second gear can be used as a hub gear, e.g., between a pinion and a wheel hub of the bicycle. The endless drive member 55 can, for example, connect the front chainring and the pinion to transmit torque from the front chainring to the pinion.

[0164] Fig. 23A and Fig. 23B show exemplary transmission systems 10, in particular according to the example from Fig. 22B. The planetary gear set 50 is arranged concentrically with respect to the input shaft I. The planetary gear set 50 includes at least three rotating elements: here, a sun gear 51, a planet carrier 52 carrying one or more planet gears 53, and a ring gear 54. Here, the planet carrier 52 is fixed to the CVT output, which is formed here by the third drive element 430, and rotates together therewith around the input shaft I. In this example, the planet carrier 52 carries several planet gears, such as two or three planet gears 53.

[0165] In the example from Fig. 23A, the planetary gear rotation axes are parallel to the input axis 411, whereas in the example of Fig. 23B the planetary gear rotation axes are arranged at an angle, in particular transversely, to the input shaft I.

[0166] The planetary gears 53 in Fig. 23A are designed as stepped planetary gears. In this way, the transmission ratio achievable with the planetary gear set can be increased compared to arrangements with non-stepped planetary gears. Therefore, each planetary gear 53 includes a large planetary element 53A and a small planetary element 53B, which are fixed to one another and rotatable together about a respective rotational axis. The large planetary element 53A of the stepped planetary gear engages the ring gear 54, whereas the small planetary element 53B engages the sun gear 51.

[0167] The first transmission 100 is selectively operable according to two different gear ratios R1, R2, where R1=1.00 and R2=2.00. R2 is provided by the planetary gear set. Clutch C1 allows the first transmission 100 to switch between the first transmission path 100A and the second transmission path 100B. Clutch C1 can be arranged either at an input of the planetary gear set or at an output of the planetary gear set 50.

[0168] Torque is transferred from the CVT input, which here is formed by the first input element 410, to the CVT output, which here is formed by the third input element 430. The planetary carrier 52 is fixed to the third input element 430 and rotates together with it about the input shaft I. Torque is transferred from the planetary carrier 52 via the stepped planet gears 53 to the sun gear 51, which in turn can be coupled to the output O via the clutch C1. If the clutch C1 is decoupled, however, no torque is transmitted through the planetary gear set 50, but instead through the first transmission path 100A, which bypasses the planetary gear set 50. Via the first transmission path 100A, torque is transferred from the third input element 430 via the one-way clutch V1 to the output O.

[0169] The output O can optionally be connected to another gear, e.g. the second gear 200, for example via an endless drive element 55, as in Fig. 22A, Fig. 22B, but it should be understood that the second gear 200 and the endless drive element 55 may be omitted.

[0170] Fig. 24A and Fig. 24B show examples of a transmission system 10 which are offset alternative configurations to those shown in Fig. 23A-23B shown examples. Fig. 24A and Fig. 24B differ from each other in terms of the configuration of the CVT unit 403, similarly to Fig. 18A and Fig. 18B.

[0171] Similar to the example from Fig. 23A-23B, one transmission path of the first transmission 100 provides a 1:1 gear ratio between the third input element 430 and the output O, and another transmission path provides a gear ratio other than one, here a gear ratio of 2.00. Instead of a coaxially arranged planetary gear set 50, as in Fig. 23A and Fig. 23B, the second transmission path 100B extends over an offset intermediate axis, which is defined here by a stationary mounting shaft 401. In comparison to the coaxial arrangement shown in Fig. 23A, Fig. 23B, the examples are from Fig. 24A and Fig. 24B is relatively compact in the axial direction. On the other hand, the coaxial arrangement of Fig. 23A-23B compared to the staggered arrangement of Fig. 24A and Fig. 24B relatively compact in the radial direction.

[0172] Fig. 25A, Fig. 25B show an example of a CVT unit 403 that is similar to the example of Fig. 5A-6C. In this example, the first concentric guide 412 includes a first guide part 412A on a first side of the first body 420A of the second drive member 420 and a second guide part 412B on an opposite second side of the first body 420A of the second drive member 420. The first guide part 412A and the second guide part 412B are mutually connected. Therefore, the first guide part 412A and the second guide part 412B can rotate together as one body. Here, the first guide part 412A and the second guide part 412B enclose the first coupling elements 411 and the second drive member 420. The first guide part 412A and the second guide part 412B are connected to form a closed cover. In this example, the first guide member 412A has a pulley 4100 formed on an outer surface thereof.The pulley 4100 may cooperate with a toothed belt, such as to drive the first drive element 410 in rotation. It is understood that the pulley may also be formed on the second guide part 412B or partly on the first drive part 412A and partly on the second drive part 412B. It is understood that more generally, the first drive element 410 may include or be connected to a pulley or a ring gear. The second drive element 420 may be mounted on a wheel hub concentrically to a wheel axle such that, to change the gear ratio of the CVT unit 403, the first axis of the first drive element 410 may be displaced from the wheel axle. It is also possible for one or more ring gears or a pulley to be connected to the second drive element 420, e.g., as described with regard to FIG. Fig. 12A, Fig. 12B.

[0173] Fig. 26A and Fig. 26B show a bicycle 1000. The bicycle 1000 includes a frame 1002 with a front fork 1005 and a rear fork 1007, and a front wheel and a rear wheel 1011, 1013 located in the front and rear forks, respectively. The bicycle 1000 further includes a crank 1017 and a front chainring 1019. The bicycle 1000 also includes a sprocket cassette 1021, for example, including one or more sprockets, with a chain 1023 threaded over the front chainring 1019 and any one of the sprockets 1021.

[0174] In the example from Fig. 26A, the bicycle comprises a hub assembly 1 as shown in Fig. 9A, Fig. 9B, Fig. 10A, Fig. 10B, Fig. 11, Fig. 12A, Fig. 12B shown.

[0175] In the example from Fig. 26B the bicycle includes a Fig. 13A, Fig. 13B, Fig. 14A, Fig. 14B, Fig. 15, Fig. 16, Fig. 17, Fig. 18A, Fig. 18B, Fig. 19A, Fig. 19B, Fig. 20, Fig. 21A, Fig. 21B, which is connected between the crank 1017 and the front chainring 1019. It is understood that the examples from Fig. 26A and Fig. 26B can be combined.

[0176] The bicycle 1000 from Fig. 26A, Fig. 26B also includes a control unit 500, here connected to a handlebar 1031, for controlling the transmission system of the bicycle. The control unit 500 may be configured to receive a first shift signal and a second shift signal and to control the CVT unit 403, the first power clutch C1, and / or the second power clutch C2 to shift gears accordingly in response to receiving the first and / or second shift signals. The shift signal may be sent, for example, wirelessly from a user interface, such as a manual shift lever device, e.g., on a handlebar of the bicycle, and / or one or more sensors, such as a torque sensor, speed sensor, cadence sensor, and / or heart rate monitor.

[0177] The first shift signal may be an upshift signal, and the second shift signal may be a downshift signal. The controller 500 may be configured to selectively control the CVT unit 403 and also the first and / or second power clutches to select the next higher system gear ratio in response to receiving the upshift signal and to select the next lower system gear ratio in response to receiving the downshift signal. The controller may also be configured to selectively control the first and / or second and / or third power clutches to select the second-nearest, third-nearest, fourth-nearest, fifth-nearest, sixth-nearest, seventh-nearest, eighth-nearest higher, or lower system gear ratio in response to receiving a rescue signal.For example, the rescue signal may include the upshift signal and the downshift signal simultaneously or within a specified time interval.

[0178] The control unit 500 can thus be connected, e.g., wirelessly, to a first actuator for actuating a relative movement between the first drive element 410 and the second drive element 420. The control unit 500 can also be connected, e.g., wirelessly, to a second actuator for actuating the first clutch C1, e.g., a powershift clutch, and, e.g., wirelessly, to a third actuator for actuating the second clutch C2, e.g., a powershift clutch. The CVT unit 403 can be operable according to any gear ratio within a continuous set of gear ratios. Each of the CVT gear ratios can be preprogrammed and, for example, adapted to the gear ratios of the first and second transmissions 100, 200. A power supply can supply power, e.g., electrical power, to the control unit 500 and the first, second, and / or third actuators and / or sensors.The power supply may, for example, include a battery.

[0179] The control unit 500 may also be arranged to operate the electric motor 450. The control unit 500 may, for example, be configured to regulate an output power or an output torque of the electric motor 450. The control unit 500 may also be configured to operate a clutch for coupling and decoupling the electric motor 450 from the transmission system 10. The electric motor 450 may be powered by a separate power source. Fig. 26A, Fig. 26B, the bicycle 1000 does not include a front derailleur and a rear derailleur, but it is understood that a front derailleur and / or a rear derailleur may be included.

[0180] Generally, the first drive element and the second drive element are movable relative to each other in a direction transverse to the first and second axes, e.g., displaceable, e.g., to provide an offset between the first axis and the second axis. To this end, the first axis may be held at a fixed location while the second axis is displaced, the second axis may be held at a fixed location while the first axis is displaced, or both the first and second axes may be displaced.Therefore, the first drive element may be arranged to be rotatable about a stationary first axis while the second drive element is rotatable about a movable second axis, or the first drive element may be arranged to be rotatable about a movable first axis while the second drive element is rotatable about a stationary second axis, or the first drive element may be arranged to be rotatable about a movable first axis while the second drive element is rotatable about a movable second axis.

[0181] When using the first drive element, the second drive element, and the third drive element, generally the first and third drive elements can be rotatable about the same first axis, while the second drive element is rotatable about the second axis. On the one hand, the first and third drive elements and, on the other hand, the second drive element are then movable relative to one another in a direction transverse to the first and second axes, e.g., displaceable, e.g., to provide an offset between the first axis and the second axis. For this purpose, the first axis can be held at a fixed position while the second axis is displaced, the second axis can be held at a fixed position while the first axis is displaced, or both the first and second axes can be displaced.Therefore, the first and third drive elements may be arranged to be rotatable about a stationary first axis while the second drive element is rotatable about a movable second axis, or the first and third drive elements may be arranged to be rotatable about a movable first axis while the second drive element is rotatable about a stationary second axis, or the first and third drive elements may be arranged to be rotatable about a movable first axis while the second drive element is rotatable about a movable second axis.

[0182] In this specification, the invention is described with reference to specific examples of embodiments of the invention. However, it will be apparent that various modifications and changes may be made thereto without departing from the spirit of the invention. For the purpose of clarity and concise description, features are described in this specification as part of the same or separate embodiments; however, alternative embodiments are also contemplated that include combinations of all or some of the features described in these separate embodiments.

[0183] In the claims, reference signs placed in parentheses are not to be interpreted as limiting the claim. The word "comprising" does not exclude the presence of features or steps other than those recited in a claim. Furthermore, the words "a" and "an" are not to be interpreted as being limited to "only one" but are instead used to mean "at least one" and do not exclude a plurality. The mere fact that certain measures are recited in mutually different claims does not indicate that a combination of those measures cannot be used to advantage. QUOTES CONTAINED IN THE DESCRIPTION

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

[0000] WO 2018 / 199757A2 [0042, 0125] WO 2020 / 085911A2 [0042, 0125] WO 2021 / 080431A1 [0042, 0125]

Claims

[1] Continuously variable transmission unit, comprising: a first drive element rotatable about a first axis; a second drive member rotatable about a second axis parallel to the first axis, the first drive member and the second drive member being movable relative to each other in a direction transverse to the first and second axes; and first coupling elements provided at a constant first radius from the first axis and at a variable second radius from the second axis for transmitting torque between the first drive element and the second drive element. [2] A continuously variable transmission unit according to claim 1, wherein at least one, or each, of the first coupling elements comprises a first and a second coupling body, and the first input element comprises a first concentric guide extending concentrically about the first axis and having a first guide part on a first side of the second input element and a second guide part on an opposite second side of the second input element, wherein the first coupling elements are coupled to the second drive element in a tangential direction and are movable relative to the second drive element in a radial direction, wherein the first and second coupling bodies are coupled to the first and second guide parts in a radial direction in the first radius from the first axis and are movable relative to the first and second guide parts in a first tangential direction, and wherein the first and the second coupling body can be coupled to the first and the second guide part in a second tangential direction opposite to the first tangential direction. [3] A transmission unit according to claim 2, wherein the first coupling body comprises a first wedging body and the second coupling body comprises a second wedging body. [4] Transmission unit according to claim 2 or 3, wherein the first coupling body and the second coupling body of a first coupling element are fixedly connected to one another. [5] Transmission according to claim 2, 3 or 4, wherein the first coupling body and the second coupling body of a first coupling element are rigidly connected to one another. [6] Transmission according to one of claims 2-5, wherein the first coupling body and the second coupling body of a first coupling element are formed as a unitary part. [7] Gear unit according to one of claims 2-6, wherein the first guide part and the second guide part are mutually connected in a radius which circumscribes the first coupling elements or is circumscribed by the first coupling elements. [8] A gear unit according to any one of claims 2-7, wherein the first guide member and the second guide member are connected to form a closed cover. [9] A gear unit according to any one of claims 3-8, wherein the first wedging body is arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the first guide part when driven in the second tangential direction, and the second wedging body is arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the second guide part when driven in the second tangential direction. [10] A gear unit according to any one of claims 3-9, wherein the first wedging body is arranged to clamp an inner and an outer surface of a circumferential wall of the first guide part when driven in the second tangential direction, and the second wedging body is arranged to clamp an inner and an outer surface of a circumferential wall of the second guide part when driven in the second tangential direction. [11] A transmission unit according to any one of claims 2-10, wherein each coupling body is configured to be in a neutral state in which free movement of the coupling body relative to the first concentric guide is enabled, and a coupled state in which the coupling body is couplingly engaged with the first concentric guide. [12] Gear unit according to claim 11, wherein each coupling body is associated with at least one roller for coupling the coupling body to the first concentric guide. [13] A gear unit according to claim 12, wherein a first end of the coupling body is provided with a converging coupling recess for cooperating with the roller. [14] A transmission unit according to any preceding claim, wherein the second drive element comprises first radial guides extending radially with respect to the second axis, the first radial guides being arranged to guide movement of the first coupling elements in the radial direction and to transmit torque in the tangential direction. [15] A gear unit according to claim 14, wherein the first radial guides comprise a radially extending projection or recess and the first coupling elements comprise a recess or projection configured to cooperate with the projection or recess of the first radial guide for axially aligning the first coupling elements with the second drive element. [16] A gear unit according to claim 14 or 15, wherein each of the first coupling elements comprises a guide wheel for running along the first radial guides. [17] A transmission unit according to claim 14 or 15, wherein each of the first coupling elements is associated with a support block for supporting on the first radial guides. [18] A gear unit according to claim 17, wherein the support block has a rounded support surface for abutting against the first radial guide. [19] A transmission unit according to claim 17 or 18, wherein the support block is pivotable relative to the first coupling element. [20] A transmission unit according to any one of claims 1-19, wherein the first drive element or the second drive element includes or is connected to a pulley or a ring gear. [21] A transmission unit according to any preceding claim, wherein the continuously variable transmission comprises: a third drive element rotatable about a third axis parallel to the second axis, the third drive element and the second drive element being movable relative to each other in a direction transverse to the third and second axes; and second coupling elements provided at a constant third radius from the third axis and at a variable fourth radius from the second axis for transmitting torque between the third drive element and the second drive element. [22] A transmission unit according to claim 21, wherein each of the second coupling elements comprises a third and a fourth coupling body, and the third drive element comprises a second concentric guide extending concentrically around the third axis and having a third guide part on a first side of the second drive element and a fourth guide part on an opposite second side of the second drive element, wherein the second coupling elements are coupled to the second drive element in a tangential direction and are movable relative to the second drive element in a radial direction, wherein the third and fourth coupling bodies are coupled to the third and fourth guide parts in a radial direction in the constant third radius from the third axis and are movable relative to the third and fourth guide parts in a fourth tangential direction, and wherein the third and fourth coupling bodies can be coupled to the third and fourth guide parts in a third tangential direction opposite to the fourth tangential direction. [23] A transmission unit according to claim 22, wherein the third coupling body is a third wedging body and the fourth coupling body is a fourth wedging body. [24] Transmission unit according to claim 22 or 23, wherein the third coupling body and the fourth coupling body of a second coupling element are fixedly connected to one another. [25] Transmission according to claim 22, 22 or 24, wherein the third coupling body and the fourth coupling body of a second coupling element are rigidly connected to one another. [26] Transmission according to one of claims 22-25, wherein the third coupling body and the fourth coupling body of a second coupling element are formed as a unitary part. [27] A transmission unit according to any one of claims 22-26, wherein the third guide part and the fourth guide part are mutually connected in a radius which circumscribes the second coupling elements or is circumscribed by the second coupling elements. [28] A transmission unit according to any one of claims 22-27, wherein the third guide member and the fourth guide member are connected to form a closed cover. [29] A gear unit according to any one of claims 23-28, wherein the third wedging body is arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the third guide part when driven in the third tangential direction, and the fourth wedging body is arranged to be wedged between a radially inner circumferential wall and a radially outer circumferential wall of the fourth guide part when driven in the third tangential direction. [30] A gear unit according to any one of claims 23-29, wherein the third wedging body is arranged to clamp an inner and an outer surface of a circumferential wall of the third guide part when driven in the third tangential direction, and the fourth wedging body is arranged to clamp an inner and an outer surface of a circumferential wall of the fourth guide part when driven in the third tangential direction. [31] A transmission unit according to any one of claims 22-30, wherein each coupling body is configured to be in a neutral position allowing free movement of the coupling body relative to the second concentric guide and a coupled state in which the coupling body is couplingly engaged with the second concentric guide. [32] Gear unit according to claim 31, wherein each coupling body is associated with at least one roller for coupling the coupling body to the second concentric guide. [33] A gear unit according to claim 32, wherein a first end of the coupling body is provided with a converging coupling recess for cooperating with the roller. [34] A transmission unit according to any one of claims 21-33, wherein the second drive element comprises second radial guides extending radially with respect to the second axis, the second radial guides being arranged to guide movement of the second coupling elements in the radial direction and to transmit torque in the tangential direction. [35] A gear unit according to claim 34, wherein the second radial guides comprise a radially extending projection or recess and the second coupling elements comprise a recess or projection configured to cooperate with the projection or recess of the second radial guide for axially aligning the first coupling elements with the second drive element. [36] A gear unit according to claim 34 or 35, wherein each of the second coupling elements comprises a guide wheel for running along the second radial guides. [37] A transmission unit according to claim 34 or 35, wherein each of the second coupling elements is associated with a support block for supporting on the second radial guides. [38] A gear unit according to claim 37, wherein the support block has a rounded support surface for abutting against the second radial guide. [39] A transmission unit according to claim 37 or 38, wherein the support block is pivotable relative to the second coupling element. [40] A transmission unit according to any preceding claim, wherein the first axis and the third axis coincide. [41] A gear unit according to any preceding claim, wherein the second drive member is pivotally movable about a pivot axis extending parallel to the first and second axes for pivotally moving relative to the first drive member in a direction transverse to the first and second axes and / or wherein the first drive member is pivotally movable about a pivot axis extending parallel to the first and second axes for pivotally moving relative to the second drive member in a direction transverse to the first and second axes. [42] A transmission unit according to claim 41, comprising a second gear concentrically coupled to the second drive member and rotatable therewith about the second axis; and a first gear drivingly connected to the second gear for transmitting torque between the first and second gears, the first gear having an axis of rotation coincident with the pivot axis. [43] A transmission unit according to claim 42, comprising an endless drive member drivingly engaging the first gear and the second gear for transmitting torque from the first gear to the second gear and / or vice versa. [44] A gear unit according to claim 43, wherein the gear unit is arranged to pivot the second drive element between a concentric position in which the first and second axes coincide and an eccentric position in which the first and second axes are offset, and wherein, if the first drive element drives the second drive element in a driven rotational direction about the second axis: the gear unit is arranged to pivot the second drive element from the concentric position to the eccentric position in a rotational direction about the pivot axis opposite to the driven rotational direction; and if the second drive element drives the first drive element in a driven rotational direction about the first axis: the gear unit is arranged to pivot the second drive element from the concentric position to the eccentric position in the driven rotational direction about the pivot axis. [45] A gear unit according to any one of claims 42-44, comprising a pivot arm for coupling the first gear to the second gear and defining a constant distance between the second axis and the pivot axis, the pivot arm extending between a first end at which the pivot arm couples to the first gear at the pivot axis and a second end at which the pivot arm couples to the second gear at the second axis. [46] A transmission unit according to any one of claims 42-45, comprising a fourth gear concentrically coupled to the second drive member and rotatable therewith about the second axis; and a third gear drivingly connected to the fourth gear for transmitting torque between the third and fourth gears, the third gear having an axis of rotation coincident with the pivot axis. [47] A transmission unit according to claim 46, wherein a torque transmission between the first and second gear wheels defines a first transmission path and a torque transmission between the third and fourth gear wheels defines a second transmission path parallel to the first transmission path; and wherein the transmission system comprises a clutch for switching the torque transmission from the first transmission path to the second transmission path and / or vice versa. [48] ​​A hub assembly for a bicycle comprising a continuously variable transmission unit according to any preceding claim. [49] The hub assembly of claim 48, comprising a hub shell for coupling to a driven wheel of the bicycle, the hub shell being coupled to the first drive member and co-rotatable about the first axis; and a sprocket concentrically coupled to the second drive member and co-rotatable about the second axis; or the hub shell being coupled to the second drive member and co-rotatable about the second axis; and a sprocket concentrically coupled to the first drive member and co-rotatable about the first axis. [50] A hub assembly according to claim 48 when dependent on at least claim 21, comprising a hub shell for coupling to a driven wheel of the bicycle, the hub shell being coupled to the first drive member and being rotatable therewith about the first axis; and a sprocket coupled to the third drive member and being rotatable therewith about the third axis. [51] A crank assembly for a bicycle comprising a continuously variable transmission unit according to any one of claims 1-47. [52] Crank assembly according to claim 51, further comprising: a first transmission, wherein the continuously variable transmission unit and the first transmission are connected in series, wherein a first transmission is selectively operable according to a first gear ratio or a second gear ratio and has a first clutch for switching the first transmission from the first gear ratio to the second gear ratio and / or vice versa. [53] A gearless transmission unit, such as for a bicycle, providing at least two discrete selectable gear ratios, comprising a transmission unit according to any one of claims 1-47. [54] A hub assembly for a bicycle including a gearless transmission unit according to claim 53. [55] A crank assembly for a bicycle, including a gearless transmission unit according to claim 53. [56] A bicycle comprising a transmission unit according to any one of claims 1-47, 53, a hub assembly according to claim 48, 49, 50 or 54, or a crank assembly according to claim 51, 52 or 55. [57] An electrically powered vehicle comprising an electric drive motor having an output power of maximum 10 kW, preferably maximum 4 kW; wherein the electric drive motor is arranged to drive a driven wheel of the vehicle, wherein a transmission unit according to any one of claims 1-47 or 53 is arranged in a transmission path between the electric drive motor and the driven wheel.

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