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DE-102025119584-B3 - Drive arrangement for a vehicle that is at least partially powered by muscle power and vehicle

DE102025119584B3DE 102025119584 B3DE102025119584 B3DE 102025119584B3DE-102025119584-B3

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.

Inventors

  • Thomas Riedisser
  • Christoph Margraf
  • Hagen Doepfert
  • Markus Scholz
  • Peter Seidel

Assignees

  • ZF FRIEDRICHSHAFEN AG

Dates

Publication Date
20260513
Application Date
20250520

Claims (10)

  1. Drive arrangement for a vehicle that is at least partially propelled 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) that is mechanically connected to the input element (61) of the reduction gear (60) for the purpose of applying a drive force, an output element (40) and a freewheel (20), wherein the output element (40) is mechanically connected to the output element (62) via the freewheel (20) for the purpose of applying an output torque, and wherein the freewheel (20) comprises at least one pivotable clamping element (21) with a clamping surface (22), the curvature of which is adapted to a curvature of an inner circumferential surface (24) of an outer ring (26) of the freewheel (20), and where 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 body (21) is pivoted into the locking position, and designed to slip when the output torque to be transmitted is greater than the locking torque.
  2. Drive arrangement according to Claim 1 , characterized in that the clamping body (21) limits a positioning 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 positioning width of the clamping body (21) in the locking position is greater than a positioning width of the clamping body (21) in a free-running position.
  3. Drive arrangement according to one of the preceding claims, characterized in that , 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 in 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 in 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 in 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 in 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 in that the drive arrangement has an oil reservoir with an oil volume which is designed such that at least a 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 in that the drive arrangement comprises a transmission (10) with 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) is mechanically connectable 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 comprises: 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 the purpose of propelling the vehicle.

Description

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. 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. DE 10 2021 213 522 B3 This concerns 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. DE 10 2023 207 492 A1 concerns a drive system for a vehicle powered at least temporarily 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. 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 via meshing gear sectors in a torque-transmitting manner, wherein the arrangement can be used in a drive unit for a muscle-powered vehicle. DE 10 2024 120 969 A1 This concerns a cam-type clutch with torque limiter function, which enables precise, stable, durable and space-saving power transmission through several cams arranged and pre-tensioned between an inner and outer ring, as well as through tilt limiting and locking sections. DE 35 01 610 C2 This concerns a freewheel clutch with an outer ring, an inner ring arranged concentrically to it and clamping elements arranged in between, in which a special design of the clamping surfaces and a holding device enables uniform slippage when a predetermined torque is exceeded, thereby achieving stable torque transmission with extended service life. It is an object of the present invention to provide an improved drive arrangement that has a long service life. 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. 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 for the purpose of applying a drive force, for example, an electric drive force. The output element is mechanically connected to the output element via the freewheel for the purpose of transmitting an output 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 element to a locked position. In the locked position, the clamping surface is aligned along the inner circumferential surface. The clamping element is designed to transmit a locking torque when it is pivoted into the locked position. The clamping element is designed to slip if the output torque to be transmitted is greater than the locking torque. The clamping element can be designed to slip at the clamping surface relative to the inner circumferential surface. The vehicle can be designed as a bicycle, e-bike, or pedelec. The drive system can be a bottom bracket drive. 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 non-rotatably connected to the input element, or the input element can be made of... 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. 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 m