Drive arrangement for a vehicle that is at least partially powered by muscle power and vehicle

Abstract

An electric drive unit (50) is mechanically connected to the input element (62) of a reduction gear (60) for applying a drive force. An output element (40) is mechanically connected to an output element (62) of the reduction gear (60) via a freewheel (20) for outputting a torque. The freewheel (20) has at least one pivotable clamping element (21) with a clamping surface (22) whose curvature is adapted to the curvature of an inner circumferential surface (24) of an outer ring (26) of the freewheel (20). The clamping surface (22) restricts the pivoting of the clamping element (21) to a locked position in which the clamping surface (22) is aligned along the inner circumferential surface (24). The clamping element (21) is designed to transmit a locking torque when the clamping element (21) is pivoted into the locking position, and to slip when the output torque to be transmitted is greater than the locking torque.

Description

[0001] The present invention relates to a drive arrangement for a vehicle that can be propelled at least partially by muscle power and to a vehicle with a drive arrangement.

[0002] Drive systems for bicycles are well-known. With the increasing complexity of these drive systems and the growing number of components and parts used in them, the costs and manufacturing effort for such drive systems also increase. From an ecological perspective alone, it is desirable for such a drive system to have a long service life.

[0003] DE 10 2021 213 522 B3 relates to a drive arrangement for a pedelec in which a bottom bracket gearbox arranged coaxially to the crankshaft is coupled to a drive wheel via a secondary drive and an electric machine arranged in the housing is connected to the output of the bottom bracket gearbox via a planetary gear set arranged coaxially to the rotor shaft and positioned on the side facing away from the machine, as well as a primary drive.

[0004] DE 10 2023 207 492 A1 relates to a drive device for a vehicle that is at least temporarily powered by muscle power, in which a drive motor can be coupled to an output shaft via a planetary gear and a traction gear and the pedal crank shaft can also be connected to the output shaft via a switchable gearbox.

[0005] DE 10 2023 207 493 A1 relates to a planet carrier arrangement for a planetary gear unit, in which a planet carrier is provided with axially spaced support elements, internal gear sectors and support sections arranged between them, and an output element can be attached to the coupling cut in a torque-transmitting manner via meshing gear sectors, wherein the arrangement can be used in a drive unit for a muscle-powered vehicle.

[0006] DE 10 2024 120 969 A1 relates to a cam-type clutch with torque limiter function, which enables precise, stable, durable and space-saving power transmission by means of several cams arranged and held under preload between an inner and outer ring, as well as inclination limiting and locking sections.

[0007] DE 35 01 610 C2 relates to a freewheel clutch with an outer ring, an inner ring arranged concentrically to it and clamping elements arranged between them, in which a special design of the clamping surfaces and a holding device enables uniform slippage when a predetermined torque is exceeded and thereby achieves stable torque transmission with extended service life.

[0008] It is an object of the present invention to provide an improved drive arrangement that has a long service life.

[0009] The problem is solved by the subject matter with the features of the independent patent claims. Advantageous further developments are the subject of the dependent claims.

[0010] In a first aspect, a drive arrangement for a vehicle that can be propelled at least partially by muscle power is provided. The drive arrangement comprises an electric drive unit, a reduction gear, an output element, and a freewheel. The reduction gear provides a transmission ratio between an input element and an output element of the reduction gear. The electric drive unit is mechanically connected to the input element of the reduction gear to input a drive force, for example, an electric drive force. The output element is mechanically connected to the output element via the freewheel to output a torque. The freewheel has at least one pivotable clamping element with a clamping surface whose curvature is adapted to or approximates the curvature of an inner circumferential surface of an outer ring of the freewheel.The clamping surface restricts the pivoting of the clamping body to a locking position. In the locking position, the clamping surface is aligned along the inner circumferential surface. The clamping body is designed to transmit a locking torque when it is pivoted into the locking position. The clamping body is designed to slip when the output torque to be transmitted is greater than the locking torque. The clamping body can be designed to slip at the clamping surface relative to the inner circumferential surface.

[0011] The vehicle can be designed as a bicycle, e-bike, or pedelec. The drive system can be a bottom bracket drive system. The output element can be a gear, a sprocket, or a pulley. The input element of the reduction gear can be a gear set element. The drive system can include an electric drive unit, such as an electric motor. The electric drive unit can have a drive shaft. The drive shaft can be rotationally fixed to the input element or form the input element itself. The input element can be designed to receive the electric drive force. The input element can be arranged parallel to the output element. The output element of the reduction gear can be arranged coaxially with the driven element.

[0012] The electric drive unit can be designed as an electric motor, for example, a synchronous or asynchronous machine. The electric drive unit can have a stator and a rotor. The electric drive unit can have a drive shaft. The rotor can form the drive shaft. The drive shaft can be mechanically connected to an input element of the reduction gear to transmit the electric drive force to the reduction gear, for example, by a rotationally fixed connection. The input element and the output element of the reduction gear can be arranged parallel to each other.

[0013] The electrical driving force can be applied to the input element in the form of a drive torque. The electrical driving force can be introduced into the reduction gear via the input element. The driving force can be present at the input element in the form of a torque and / or a rotational speed.

[0014] The driving force can be converted via the reduction gear; for example, the rotational speed can be reduced. The converted driving force can be output at the output element in the form of an output torque. The reduction gear can include a traction element, such as a belt drive or a chain drive. The reduction gear can include a gear set, such as a planetary gear set.

[0015] The planetary gear set can comprise a sun gear, a planet carrier, several planet pins, several planet gears, and a ring gear. The planet pins can be fixed to the planet carrier. Each planet pin can rotatably support a planet gear. At least one of the planet gears can mesh with both the sun gear and the ring gear. The planetary gear set can be configured as a positive or negative planetary gear set. The sun gear can have spur gear teeth.

[0016] The vehicle may have a further input element, for example a mechanical input element, for applying a mechanical drive force. The mechanical input element may be mechanically connected to the output element via a transmission. The mechanical input element may be designed as a crankshaft. At least one crank arm may be fixedly connected to the mechanical input element at one end in an axial direction. The mechanical input element may have an axis of rotation that is rotatable about the mechanical input element. The axis of rotation may be oriented in the axial direction. A radial direction may be oriented substantially perpendicular to the axial direction. A circumferential direction may be oriented around the axis of rotation. A pedal may be attached at one end in the radial direction of the crank arm.The mechanical input element can be arranged coaxially with at least one of the output element and the driven element. The mechanical input element can extend axially through at least one of the output element and the driven element.

[0017] If two elements are mechanically connected, they are coupled to each other directly or indirectly in such a way that a movement of one element causes a reaction of the other. For example, a mechanical connection can be provided by a positive-locking or friction-locking connection. The mechanical connection can correspond to the meshing of corresponding gear teeth on the two elements. Further elements, such as one or more spur gear stages, can be provided between the elements. A permanently rotationally fixed connection between two elements, on the other hand, is understood to be a connection in which the two elements are rigidly coupled to each other in all intended states of the transmission. The elements can be individual components rigidly connected to each other or even as a single piece.A switching element, such as a freewheel, clutch, or brake, can selectively establish or disengage a rotationally fixed connection between two elements. The freewheel can be designed to establish a rotationally fixed connection only in one locked direction of rotation, while allowing free rotation of the elements relative to each other in the opposite direction. Therefore, the freewheel can have both a locked and a free-running state.

[0018] The output torque can be used to drive or propel the vehicle. The output element can be configured to transmit the output torque via an output transmission, such as a chain or belt drive, to a driven traction element, such as a rear wheel.

[0019] The output element of the reduction gear can be configured to be rotationally fixed to the output element of the drive assembly via the freewheel in the locking direction. Alternatively, the output element of the reduction gear can be configured to rotate freely relative to the output element of the drive assembly via the freewheel in the freewheel direction. The output element of the reduction gear can be designed as a sprocket or pulley.

[0020] The freewheel can be designed as a freewheel clutch or a retractable clutch. The freewheel can have multiple clamping elements. The clamping elements can be arranged circumferentially, for example, evenly spaced or in groups. A group of clamping elements, for example, three clamping elements, can be spaced close together circumferentially, for example, at a uniform distance. Several of these groups can be arranged circumferentially, for example, evenly spaced. The freewheel can have an inner ring and an outer ring. The clamping element can be arranged radially between the inner ring and the outer ring of the freewheel.

[0021] The clamping element can have a locking position and a free-running position. The clamping element can be pivotable from the free-running position to the locking position, for example, about a pivot axis. The pivot axis can be aligned parallel to a rotation axis of the free-running mechanism, for example, the rotation axis of the output element. The free-running mechanism can provide the locking state when the clamping element is in the locking position. The free-running mechanism can provide the free-running state when the clamping element is in the free-running position.

[0022] The outer ring of the freewheel can have an inner circumferential surface. This inner circumferential surface can form a running surface, for example, for a rolling element. The inner ring of the freewheel can have an outer circumferential surface. This outer circumferential surface can also form a running surface, for example, for the rolling element. In the locked position, the clamping surface of the clamping element can exert a high compressive or normal force on the inner circumferential surface, such as the running surface. This high compressive force can generate a high frictional force. This high frictional force can form the locking torque that can be transmitted via the freewheel. The locking torque can be a friction-based torque. The locking torque can be transmitted between the inner and outer rings.In the freewheel position, the clamping surface of the clamping element, or another surface such as a freewheel surface, can exert a small compressive or normal force on the inner circumferential surface, such as the running surface. This force may be lower than the high compressive force. The small compressive force may be so low that the inner and outer rings are essentially free to rotate relative to each other, for example, in the freewheel direction of rotation. The locking torque of the freewheel can be related to the number of clamping elements. The locking torque can be reduced by decreasing the number of clamping elements. The locking torque can be increased by increasing the number of clamping elements.

[0023] In the locked position, the clamping surface can be aligned along the inner circumferential surface. In the locked position, the clamping surface can be in contact with the inner circumferential surface. In the free-running position, the clamping surface can be pivoted relative to the inner circumferential surface, for example, pivoted radially inwards. In the free-running position, the clamping surface can be released or removed from the inner circumferential surface.

[0024] The clamping element can have a stop surface. The clamping surface can also form the stop surface. The stop surface can be offset circumferentially from a contact area of ​​the clamping element with the outer circumferential surface of the inner ring. The stop surface can restrict the pivoting of the clamping element from the freewheel position to the locked position. This can prevent the clamping element from flipping over. Furthermore, this can limit the transmissible torque of the freewheel to the locking torque. If a torque between the inner ring and the outer ring exceeds the locking torque, this can lead to slippage of the outer ring relative to the clamping element or the inner ring.

[0025] This provides overload protection for components of the reduction gear and the electric drive unit during torque surges, such as those occurring during dynamic pedal inputs or via the driven traction element, during a dynamic race start using the pedals, or similar situations. This increases the robustness of the drive assembly and reduces the risk of component failure in the reduction gear. Consequently, the components of the reduction gear can be designed to be more compact. This allows for a drive assembly with low costs, a small installation space, and low weight.

[0026] The freewheel can have a preload element, for example, a spring element. The preload element can preload the freewheel body towards the locked position. The freewheel body can have a preload section. The preload element can bear against the preload section, for example, a preload surface. A contact area between the preload section and the preload element can be offset circumferentially from the contact area of ​​the clamping body with the outer circumferential surface of the inner ring. The preload element can generate an actuating torque on the freewheel body, which preloads the freewheel body towards the locked position. This allows a preload force, for example, a compressive force or normal force, to be exerted by the clamping surface or the freewheel surface of the clamping body on the inner circumferential surface, for example, the running surface, which is small, for example, as described above. The preload element can be ring-shaped.The preload element can be designed as a worm spring. The preload element can extend circumferentially between the inner ring and the outer ring.

[0027] The freewheel may include a cage. The cage may be designed to position the freewheel elements and / or the rolling elements in the circumferential and / or axial direction. The cage may also be designed to position the preload element.

[0028] In one embodiment of the drive arrangement, the clamping element can be designed to limit the radial opening width between the outer and inner rings by means of the clamping surface when the clamping element is pivoted into the locked position. The opening width of the clamping element in the locked position can be greater than the opening width of the clamping element in the free-running position.

[0029] The clamping element can have an outer contour that, apart from the clamping surface, is rounded, elliptical, egg-shaped, or similar. The clamping range can result from the extension of the clamping element in the radial direction. The clamping range can vary for different positions of the clamping element, for example, the locked position and the free-running position. The further the clamping element is pivoted from the free-running position to the locked position, the greater the clamping range can become. The clamping range can increase continuously. The clamping range can depend on pivoting the clamping element, for example, around the pivot axis. The clamping range can be limited, for example, by the stop surface.

[0030] In one embodiment of the drive arrangement, the curvature of the clamping surface can be adapted to ensure surface contact between the clamping surface and the inner circumferential surface in the locked position of the clamping element. This surface contact can extend along the entire clamping surface. The curvature of the clamping surface can be substantially equal to or slightly greater than the curvature of the inner circumferential surface of the outer ring. This surface contact can reduce wear on both the clamping surface and the inner circumferential surface, resulting in a drive arrangement with a long service life.

[0031] In one embodiment of the drive arrangement, at least one of the outer ring and one of the inner ring can be designed to exhibit radial elasticity adapted to the locking torque. Both the outer ring and the inner ring can exhibit radial elasticity adapted to the locking torque. The radial elasticity can be adjusted by selectively reducing the stiffness of the outer ring or inner ring in the radial direction. Alternatively, the radial elasticity can be adjusted by the thickness of the outer ring or inner ring in the radial direction. The thickness can be dimensioned such that the compressive force required to provide the locking torque causes deformation, for example, expansion or compression, of the outer ring or inner ring.

[0032] The radial elasticity can be configured for a cylindrically homogeneous deformation, such as expansion or compression. This allows the inner circumferential surface and / or the outer circumferential surface, or a running surface formed by it, to maintain a cylindrical shape during deformation. This configured radial elasticity can be combined with the freewheel, which has a bearing function, as described later. The locking torque can be specifically adjusted to a certain value via the radial elasticity. The locking torque can be set to a value lower than the breaking load torque of the components of the reduction gear and the electric drive unit, for example, the lowest breaking load torque of one of the components.

[0033] In one embodiment of the drive arrangement, the freewheel can have at least one rolling element with a bearing function. The freewheel can form a bearing arrangement via this at least one rolling element. A number of rolling elements can be arranged circumferentially, for example, evenly spaced. The rolling element can be arranged radially between the outer and inner rings. The rolling element can be in contact with the running surfaces of the outer and inner rings. Three clamping elements, for example, as a group of clamping elements, and one rolling element can be arranged alternately circumferentially. The freewheel can have at least five rolling elements. The bearing arrangement can provide radial support for the inner ring relative to the outer ring. The rolling element can be designed as a cylinder or a ball. This can reduce tolerance-related fluctuations in the locking torque.

[0034] In one embodiment of the drive arrangement, the inner ring can be non-rotatably connected to the output element via a shaft-hub connection, for example, at an inner circumferential surface of the inner ring. The shaft-hub connection can be designed as a splined shaft connection, toothed shaft connection, serrated gearing, or the like.

[0035] In one embodiment of the drive arrangement, the output element of the reduction gear and the outer ring can be formed in one piece.

[0036] The output element can be arranged axially offset from the outer ring. The output element can be arranged axially adjacent to or near the outer ring. The output element and the outer ring can be formed from a common output ring element, for example, as a single piece.

[0037] In one embodiment of the drive arrangement, the drive arrangement can have an oil reservoir with an oil volume that can be configured such that at least a section of the freewheel is located below the oil surface of the oil volume. The oil can be contained within a gearbox and / or the reduction gear. The oil can have lubricating and / or cooling properties. At least one of the clamping elements can be located at least partially below the oil level. The inner ring and the outer ring can be located partially below the oil level. The freewheel can be arranged such that oil lubrication of the freewheel is ensured, for example, even during vehicle operation. This ensures a homogeneous lubrication condition of the freewheel. A homogeneous friction condition, for example, between the inner circumferential surface of the outer ring and the clamping surface of the clamping element, can be ensured.Fluctuations in the locking torque can be reduced. This increases the reproducibility of the overload protection function of the freewheel.

[0038] In one embodiment of the drive arrangement, the drive arrangement can comprise the transmission with at least one planetary gear set, the mechanical input element, and the mechanical output element, wherein the transmission provides a transmission ratio between the mechanical input element and the mechanical output element. The mechanical output element can be mechanically connected to the output element via a second freewheel, for example, in a locking direction. The transmission can comprise further mechanical output elements, for example, a second mechanical output element. The second mechanical output element can be mechanically connected to the output element, for example, in a rotationally fixed manner. The mechanical output element can be designed as a ring gear and formed integrally with an outer ring of the second freewheel.The second mechanical output element can be designed as a sun gear, for example, of a planetary gear set. The second freewheel can be arranged axially adjacent to the first freewheel. The inner ring and one inner ring of the second freewheel can be formed by a common inner ring.

[0039] The planetary gear set can be operated in a locked configuration via the second freewheel. In this case, the differential speed between the ring gear and the sun gear can be essentially zero. Most of the mechanical output torque can then be transmitted via the ring gear, and thus via the second freewheel (locked in the blocking direction), to the rotationally fixed output element. A small portion of the mechanical output torque can be transmitted to the output element via the sun gear. The mechanical output torque that can be transmitted to the output element can therefore be largely determined by the transmittable torque of the second freewheel.

[0040] The gearbox can be mechanically connected to the output element via a second freewheel to transmit the mechanical output torque. This second freewheel can be provided in addition to the previously described freewheel, for example, the first freewheel. The second freewheel can be arranged axially adjacent to or near the first freewheel. The inner ring and one inner ring of the second freewheel can be formed by a common inner ring.

[0041] The mechanical input element and the mechanical output element can be arranged coaxially to each other and to the output element. The mechanical input element of the gearbox can be arranged parallel to the axis of the electric drive unit or the input element.

[0042] The transmission can provide multiple gear ratios between the mechanical input element and the mechanical output element. These gear ratios can be switchable, for example, via at least one switching element. The transmission can be designed as a manual transmission. The transmission can have multiple gear sets, for example, planetary gear sets, to provide the gear ratios. The planetary gear sets can form components of the transmission. The transmission can have other components, such as switching elements, freewheels, and the like. The transmission can have at least one planetary gear set. The mechanical output element can be designed as a ring gear, for example, of the planetary gear set, which can be integrally formed with the outer ring of the second freewheel. The transmission can have four planetary gear sets.At least one or all of the planetary gear sets can be configured as negative planetary gear sets. The transmission can have multiple shift elements, for example, four shift elements. The shift elements can be configured as brakes. The transmission can have multiple freewheels, for example, four freewheels. The transmission can have multiple gears, for example, 13 or 16 gears. A gear can be associated with a gear ratio between the mechanical input element and the mechanical output element.

[0043] The common inner ring can extend axially in a sleeve-like shape. The common inner ring can have a connecting section for a rotationally fixed connection to the output element. The connecting section can be designed for the shaft-hub connection. The common inner ring can have a support section for positioning the common inner ring relative to the output element, for example, in the radial direction. The support section can extend radially in a disc-like shape, for example, from the common inner ring inwards to the output element. An inner circumference of the support section can abut an outer circumference of the output element. The connecting section can be arranged on a first side of the inner ring. The support section can be arranged on a second side of the inner ring opposite the first side.

[0044] A second aspect describes a vehicle with a drive system as described in the first aspect. This vehicle is at least partially muscle-powered. Further characteristics, advantages, and effects for the second aspect can be derived from one of the preceding aspects. Furthermore, characteristics, advantages, and effects of the second aspect also define characteristics, advantages, and effects for the preceding aspects.

[0045] The vehicle is at least partially propelled by muscle power. The vehicle has at least one traction element for propelling itself, which is mechanically connected to the output element. The traction element can be a drive wheel, for example, a driven rear wheel. The traction element can be mechanically connected to the output element via the output transmission, for example, a chain drive, a belt drive, or a belt drive. The vehicle may have other devices, such as a steering system and a braking system. Fig. Figure 1a is a schematic representation of an embodiment of a freewheel for a drive arrangement of a vehicle that can be driven at least partially by muscle power in a freewheeling state. Fig. 1b is a schematic representation of the freewheel from Fig. 1a in a transitional state. Fig. 1c is a schematic representation of the freewheel from Fig. 1a in a locked state. Fig. Figure 2 is a sectional view of a schematic representation of an embodiment of the drive arrangement. Fig. Figure 3 is a sectional view of a schematic representation of another embodiment of the drive arrangement. Fig. Figure 4 is a detail of a sectional view of a schematic representation of another embodiment of the drive arrangement. Fig. Figure 5 is a detail of a side view of a schematic representation of another embodiment of the drive arrangement. Fig. Figure 6 is a detail of a sectional view of a schematic representation of another embodiment of the drive arrangement. Fig. Figure 7 is a side view of a schematic representation of the vehicle, which is at least partially powered by muscle power.

[0046] Fig. Figure 1a is a schematic representation of an embodiment of a freewheel 20 for a drive arrangement of a vehicle that is at least partially driven by muscle power in a freewheeling state. The freewheel 20 has an inner ring 27, an outer ring 26, and a number of clamping elements 21. The clamping elements 21 are arranged radially between the inner ring 27 and the outer ring 26. The clamping element 21 is in a freewheeling position. The clamping element 21 is pivotable between the freewheeling position and a locked position.

[0047] The clamping body 21 has a clamping surface 22 whose curvature is adapted to the curvature of an inner circumferential surface 24 of the outer ring 26 for surface contact. The clamping body 21 has a free-running surface 31 that is in contact with the inner circumferential surface 24. In the free-running position, the clamping surface 22 is pivoted relative to the inner circumferential surface 24 and detached from it. In the free-running position, the inner ring 27 is freely rotatable in a free-running direction relative to the outer ring 26.

[0048] The freewheel 20 has a preload element 29 designed as a ring spring, which extends radially between the inner ring 27 and the outer ring 26 in the circumferential direction. The preload element 29 rests against a preload section 25 of the clamping body 21 and presses it radially inwards. A contact area between the preload section 25 and the preload element 29 is arranged circumferentially offset from a contact area between the clamping body 21 and an outer circumferential surface of the inner ring 27. This generates an adjusting torque that pulls the clamping body 21 into a Fig. Pre-tensioned towards the locking position shown in 1c.

[0049] Fig. 1b is a schematic representation of the freewheel 20 from Fig. 1a in a transitional state. The outer ring 26 begins to rotate in a locking direction relative to the inner ring 27. This increases the setting torque via a contact area between the free-running surface 31 of the clamping body 21 and the inner circumferential surface 24 of the outer ring 26, so that the clamping body 21 is pivoted from the free-running position to the locked position.

[0050] Fig. 1c is a schematic representation of the freewheel 20 from Fig. 1a in a locked position. The outer ring 26 has rotated so far in the locking direction relative to the inner ring 27 that the clamping element 21 has pivoted into the locked position. The clamping surface 22 is aligned along the inner circumferential surface 24 and is in surface contact with the inner circumferential surface 24. The clamping element 21 in the locked position has a clearance that extends radially between the outer circumferential surface of the inner ring 27 and the inner circumferential surface 24 of the outer ring 26. The clamping surface 22 has a stop surface 30 which, with respect to the contact area of ​​the clamping element 21 with the inner ring 27, is inclined to the left in the circumferential direction. Fig. The clamping body 21 is arranged offset from position 1c. The stop surface 30 limits the pivoting of the clamping body 21 from the freewheel position to the locked position. The clamping body 21 cannot pivot beyond the locked position. Thus, the freewheel 20 provides overload protection for components of a system with respect to Fig. 2 and Fig. The 3 described reduction gear 60 and an electric drive unit 50 are ready. This extends the service life of the drive arrangement.

[0051] In the locked position, the clamping surface 22 exerts a normal force on the inner circumferential surface 24. This generates a frictional torque, which forms a locking torque. Therefore, the clamping body 21 is designed to transmit a friction-based locking torque when it is pivoted into the locked position. If the output torque to be transmitted exceeds the locking torque, the clamping body 21 is designed to slip via the stop surface 30. The output torque that can be transmitted via the freewheel 20 is limited to the locking torque.

[0052] Fig. Figure 2 is a sectional view of a schematic representation of an embodiment of the drive arrangement. The drive arrangement comprises an electric drive unit 50 and a reduction gear 60, which provides a transmission ratio between an input element 61, in this case a sun gear, and an output element 62 of the reduction gear 60. The electric drive unit has a stator and a rotor with a drive shaft. The drive shaft forms the input element 61 for supplying an electric driving force to the reduction gear 60.

[0053] The reduction gear 60 comprises a planetary gear set and a traction element drive, in this case a chain drive. A sun gear of the planetary gear set forms the input element 61. A planet carrier is rotationally fixed to an input sprocket of the chain drive. The input sprocket is mechanically connected via a chain to an output sprocket, which forms the output element 62.

[0054] The input element 61 is arranged axially parallel to the output element 62 and a driven element 40. The output element 62 is connected to the driven element 40, in this case a sprocket, via the freewheel 20 for the output torque, in this case an electrical output torque, in a rotationally fixed manner in the locking direction. The output element 62 and the outer ring 26 of the freewheel 20 are formed in one piece. The inner ring 27 is rotationally fixed to the driven element 40.

[0055] The drive assembly further comprises a mechanical input element 11, in this case a pedal crank shaft, for applying a mechanical drive force to the drive assembly. The mechanical input element 11 is rotatably mounted on a first side relative to the output element 40 via two bearing arrangements 44 and sealed to an outside of the drive assembly by a sealing element 43. On a second side opposite the first side, the mechanical input element 11 is rotatably mounted on a housing of the drive assembly via a bearing arrangement 45 and sealed to the outside of the drive assembly by a sealing element 46. The output element 40 is rotatably mounted on the housing via a bearing arrangement 42 and sealed to the outside of the drive assembly by a sealing element 41. The input sprocket is rotatably mounted on the housing via a bearing arrangement 47.The drive shaft is rotatably mounted on the housing via two bearing assemblies 48. A drive compartment of the housing is sealed from a gear compartment of the housing by a sealing element 49. The sealing element 49 is arranged between the two bearing assemblies 48. In one embodiment, the sealing element 49 can be arranged outside the two bearing assemblies 48.

[0056] The housing forms an oil reservoir with an oil surface, represented by a dashed line. The freewheel 20 is arranged such that a section of it is located below the oil surface. This ensures a homogeneous lubrication of the freewheel 20.

[0057] Fig. Figure 3 is a sectional view of a schematic representation of another embodiment of the drive arrangement. In this case, the drive arrangement comprises a gearbox 10. The gearbox 10 provides a switchable transmission ratio between the mechanical input element 11 and a mechanical output element 12 of the gearbox 10. The mechanical input element 11 is arranged coaxially to the mechanical output element 12 and the output element 40 and extends axially through the mechanical output element 12 and the output element 40. The gearbox 10 has four planetary gear sets. The gearbox 10 has four switching elements and four freewheels. The planetary gear sets are interconnected via the switching elements and freewheels in such a way that they provide a plurality of switchable transmission ratios.

[0058] Fig. Figure 4 is a detail of a sectional view of a schematic representation of a further embodiment of the drive arrangement. The gearbox 10 is operatively connected to the output element 40 via the second freewheel 20' in a locking direction of rotation of the second freewheel 20' for the purpose of transmitting the mechanical output torque. An outer ring 26' of the second freewheel 20' is integrally formed with a mechanical output element 12 of the gearbox 10, which is designed as a ring gear. The inner ring 27 and the inner ring 27' of the second freewheel 20' are formed by a common inner ring. The common inner ring has a connection section on a first side, which is rotationally fixed to the output element 40 via a shaft-hub connection. On a second side opposite the first side, the common inner ring has a support section, which is designed to position the common inner ring relative to the output element 40 in the radial direction.The freewheel 20 and the second freewheel 20' also have a cage 28 for positioning the clamping elements 21 in the circumferential direction.

[0059] Fig. Figure 5 shows a detail of a side view of a schematic representation of another embodiment of the drive arrangement. The freewheel 20 has a number of rolling elements 32, in this case cylindrical rollers, and thus forms a bearing assembly. The rolling elements 32 are arranged uniformly in the circumferential direction. One rolling element 32 and three clamping elements 21 are arranged alternately in the circumferential direction. The inner circumferential surface 24 of the outer ring 26 and the outer circumferential surface of the inner ring 27 each form a running surface for the rolling elements 32.

[0060] Fig. Figure 6 is a detail of a sectional view of a schematic representation of another embodiment of the drive arrangement. The present embodiment differs from the one described in relation to Fig. In the embodiment described in section 4, the outer ring 26, 26' and the inner ring 27, 27' of both the freewheel 20 and the second freewheel 20' have a radial elasticity adapted to the locking torque that can be transmitted via the freewheel 20, 20'. For this purpose, the thickness of the respective outer ring 26, 26' and the respective inner ring 27, 27' is reduced in the radial direction. The support section has a disc-shaped form and extends radially inwards from the common inner ring to the output element 40. The connecting section is connected to the common inner ring via an inner section extending radially inwards from the common inner ring. The radial elasticity allows for homogeneous deformation of the respective outer ring 26, 26' and the respective inner ring 27, 27' when the respective clamping elements 21 are in the locked position.This ensures that the cylindrical shape of the respective running surfaces of the respective outer ring 26, 26' and the respective inner ring 27, 27' is maintained during deformation.

[0061] Fig.Figure 7 is a side view of a schematic diagram of a vehicle, in this case an e-bike, that is at least partially propelled by muscle power. The drive arrangement is designed as a bottom bracket drive. The mechanical input element 11 of the gearbox 10 is mechanically driven by a mechanical drive force via two crank arms, each with a pedal. The electric drive unit 50 provides an electric drive force for propelling the vehicle. The output element 40 is mechanically connected to the gearbox 10 and the reduction gear 60 to output a superimposed drive force consisting of the electric and mechanical drive forces. The output element 40 is mechanically connected via a chain drive to a traction element 70, designed as a driven rear wheel, for propelling the vehicle. Reference sign 10 gearboxes 11 Mechanical input element 12 Mechanical output element 15 First planetary gear set 16 Second planetary gear set 17 Third planetary gear set 18 Fourth planetary gear set 20 Freewheel 20' Second freewheel 21 clamping bodies 22 clamping surface 24 Inner circumference area 25 Pre-tensioning section 26 outer ring 26' Outer ring of the second freewheel 27 inner ring 27' Inner ring of the second freewheel 28 cage 29 Preload element 30 rolling elements 40 Output element 41 Sealing element 42 Storage facility 43 Sealing element 44 Storage facility 45 Storage facility 47 Storage facility 48 Storage facility 49 Sealing element 50 Electric drive unit 60 reduction gears 61 Input element of the reduction gear 62 Output element of the reduction gear 70 traction element

Claims

[1] Drive arrangement for a vehicle that can be propelled at least partially by muscle power, wherein the drive arrangement comprises: a reduction gear (60) that provides a transmission ratio between an input element (61) and an output element (62) of the reduction gear (60), an electric drive unit (50) which is mechanically connected to the input element (61) of the reduction gear (60) for the purpose of applying a drive force, a driven element (40) and a freewheel (20), wherein the driven element (40) is mechanically connected to the output element (62) via the freewheel (20) to output a driven torque, and wherein the freewheel (20) has at least one pivotable clamping body (21) with a clamping surface (22), whose curvature is adapted to a curvature of an inner circumferential surface (24) of an outer ring (26) of the freewheel (20), and wherein the clamping surface (22) restricts the pivoting of the clamping body (21) to a locking position in which the clamping surface (22) is aligned along the inner circumferential surface (24), and wherein the clamping body (21) is designed to transmit a locking torque when the clamping element (21) is pivoted into the locking position, and is designed to prevent slippage if the output torque to be transmitted is greater than the locking torque. [2] Drive arrangement according to claim 1, characterized by , that the clamping body (21) limits a setup width in a radial direction between the outer ring (26) and an inner ring (27) through the clamping surface (22) when the clamping body (21) is pivoted into the locking position, and wherein The opening width of the clamping body (21) in the locked position is greater than the opening width of the clamping body (21) in a free-running position. [3] Drive arrangement according to one of the preceding claims, characterized by , that the curvature of the clamping surface (22) is adapted for surface contact of the clamping surface (22) with the inner circumferential surface (24) in the locking position of the clamping body (21). [4] Drive arrangement according to one of the preceding claims, characterized by , that at least one of the outer ring (26) and the inner ring (27) is designed such that it has a radial elasticity adapted to the locking torque. [5] Drive arrangement according to one of the preceding claims, characterized by that the freewheel (20) has at least one rolling element (32) with a bearing function. [6] Drive arrangement according to one of the preceding claims, characterized by , that the inner ring (27) is connected to the output element (40) in a rotationally fixed manner via a shaft-hub connection. [7] Drive arrangement according to one of the preceding claims, characterized by, that the output element (62) of the reduction gear (60) and the outer ring (26) are formed in one piece. [8] Drive arrangement according to one of the preceding claims, characterized by , that the drive arrangement has an oil reservoir with an oil volume which is designed such that at least one section of the freewheel (20) is arranged below an oil surface of the oil volume. [9] Drive arrangement according to one of the preceding claims, characterized by that the drive arrangement a transmission (10) comprising at least one planetary gear set, a mechanical input element (11) and a mechanical output element (12), wherein the transmission (10) provides a transmission ratio between the mechanical input element (11) and the mechanical output element (12), the mechanical output element (12) can be mechanically connected to the output element (40) via a second freewheel (20'), the mechanical output element (12) is designed as a ring gear and is formed integrally with an outer ring (26') of the second freewheel (20'), the second freewheel (20') is arranged in an axial direction adjacent to the freewheel (20), and the inner ring (27) and an inner ring (27') of the second freewheel (20') are formed by a common inner ring. [10] Vehicle that can be propelled at least partially by muscle power, wherein the vehicle has: a drive arrangement according to one of the preceding claims and a traction element (70) which is mechanically connected to the output element (40) of the drive arrangement for moving the vehicle.

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