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DE-102024132585-A1 - Freewheel for a vehicle's drivetrain, drivetrain for a vehicle

DE102024132585A1DE 102024132585 A1DE102024132585 A1DE 102024132585A1DE-102024132585-A1

Abstract

The invention relates to a freewheel (19) for a vehicle drivetrain, comprising a clamping device (2) with a coupling sleeve (3) for transmitting torque between a drive shaft (4) and an output shaft (5), a coupling spring (6) for moving the coupling sleeve (3) into a first torque-transmitting switching position between the drive shaft (4) and the output shaft (5); a switching device (7) configured to switch the clamping device (2) from the first switching position to a second switching position for decoupling the drive shaft (4) from the output shaft (5), characterized in that further comprising an overload protection device (8) configured to limit a decoupling force for decoupling the drive shaft (4) from the output shaft (5) to a maximum value. The invention further relates to a vehicle drivetrain.

Inventors

  • Matthias Feuerbach
  • Martin Dressel
  • Tobias Heumann
  • Andreas Strauss

Assignees

  • Schaeffler Technologies AG & Co. KG

Dates

Publication Date
20260513
Application Date
20241108

Claims (10)

  1. Freewheel (19) for a drive train of a vehicle, comprising a clamping device (2) with a coupling sleeve (3) for transmitting torque between a drive shaft (4) and an output shaft (5), a coupling spring (6) for bringing the coupling sleeve (3) into a first torque-transmitting switching position between the drive shaft (4) and the output shaft (5); a switching device (7) which is configured to switch the clamping device (2) from the first switching position to a second switching position for decoupling the drive shaft (4) from the output shaft (5), characterized in that further comprising an overload protection device (8) which is configured to limit a decoupling force for decoupling the drive shaft (4) from the output shaft (5) to a maximum value.
  2. Freewheel after Claim 1 , characterized in that the overload protection device (8) comprises an outer sleeve (9) and a decoupling spring (10), wherein the decoupling spring (10) is in operative connection with the coupling sleeve (3), wherein the overload protection device (8) is configured to pre-tension the outer sleeve (9) against the decoupling spring (10) when switching from the first switching position to the second switching position, so that the decoupling force acts on the coupling sleeve (3) of the clamping device (2) for switching from the first switching position to the second switching position.
  3. Freewheel after Claim 2 , characterized in that the maximum value of the decoupling force of the decoupling spring (10) is higher than a maximum value of a coupling force of the coupling spring (6) of the switching device (7). // wherein the spring stiffness of the decoupling spring is greater than the spring stiffness of the coupling spring.
  4. Freewheel after Claim 2 , characterized in that the outer sleeve (9) has a ramp profile (11) for pre-tensioning the decoupling spring (11).
  5. Freewheel after one of the Claims 2 until 4 , characterized in that the coupling sleeve (3) has a stop (12) for supporting the decoupling spring (10).
  6. Freewheel after one of the Claims 2 until 5 , characterized in that the switching device (7) has a solenoid (13) with a switching element (14) for switching the clamping device (7), wherein the switching element (14) is configured to preload the outer sleeve (9) against the decoupling spring (10) when switching from the first switching position to the second switching position.
  7. Freewheel after Claim 6 , characterized in that the switching element (14) comprises a rolling bearing (15) which is arranged to preload the outer sleeve (9) against the decoupling spring (10) when switching from the first switching position to the second switching position.
  8. Freewheel according to one of the preceding claims, characterized in that the clamping device (7) comprises at least one clamping element (16) for coupling the drive shaft (4) and the output shaft (5), wherein the coupling sleeve (3) clamps the at least one clamping element (16) in the first switching position, so that a torque can be transmitted.
  9. Drive train for a vehicle, comprising a freewheel (1) after one of the Claims 1 until 8 .
  10. Powertrain Claim 9 , characterized in that the vehicle is an electric vehicle or a hybrid vehicle.

Description

The invention relates to a freewheel for a vehicle drive train, comprising a clamping device with a coupling sleeve for transmitting torque between a drive shaft and an output shaft, a coupling spring for bringing the coupling sleeve into a first torque-transmitting switching position between the drive shaft and the output shaft, a switching device configured to switch the clamping device from the first switching position to a second switching position for decoupling the drive shaft from the output shaft, and a vehicle drive train. Freewheels are used in vehicles to disconnect drive systems, especially electric motors, from the vehicle's wheels. This prevents the drive system from being dragged along when it's not needed, which can improve energy efficiency. Freewheels have mechanical devices that disengage the drive system within the respective drivetrain. External factors, such as uneven road surfaces, can damage the freewheel. In this context, it has become apparent that there is a need to provide a freewheel for a vehicle's drivetrain, in particular a need to provide an improved freewheel for a vehicle's drivetrain. It is therefore an object of the present invention to eliminate, or at least partially eliminate, the disadvantages described above for freewheels in a vehicle drivetrain. In particular, it is an object of the present invention to provide an improved freewheel for a vehicle drivetrain. This problem is solved according to the invention in a freewheel of the generic type by providing an overload protection device to limit a decoupling force for decoupling the drive shaft from the output shaft to a maximum value. In particular, the problem is solved by a freewheel with the features of independent claim 1. Furthermore, the problem is solved by a drive train for a vehicle according to the features of independent claim 9. Features disclosed in connection with the freewheel according to the invention naturally also apply in connection with the drive train according to the invention, and vice versa, so that the disclosure of the individual aspects of the invention always makes or can make reciprocal reference. According to a first aspect of the present invention, a freewheel for a vehicle drivetrain is provided, comprising a clamping device with a coupling sleeve for transmitting torque between a drive shaft and an output shaft, a coupling spring for bringing the coupling sleeve into a first torque-transmitting switching position between the drive shaft and the output shaft, a switching device configured to switch the clamping device from the first switching position to a second switching position for decoupling the drive shaft from the output shaft, characterized in that further comprising an overload protection device configured to limit a decoupling force for decoupling the drive shaft from the output shaft to a maximum value. In this context, the term "freewheel" refers in particular to a structural device designed to establish and release a connection for torque transmission between a first shaft and a second shaft. The first shaft can preferably be a drive shaft. The second shaft can preferably be an output shaft. In this context, the term "drivetrain" refers to an assembly designed to transmit the power of an engine to the wheels. The drivetrain includes, among other things, a drive shaft and an output shaft. The engine is preferably an electric motor. A differential is preferably arranged between the engine and the drive shaft. The output shaft is preferably connected to a wheel of the vehicle. In this context, the term "vehicle" refers specifically to a vehicle with an electric motor drivetrain. The vehicle can be an electric vehicle (i.e., BEV). The vehicle can be a hybrid vehicle (i.e., HEV). In this context, the term clamping device refers in particular to a structural device designed to couple a drive shaft with an output shaft for torque transmission. In this context, the term coupling sleeve refers in particular to a structural element designed to enable a mechanical connection for torque transmission between a drive shaft and an output shaft. The coupling sleeve can, for example, have structural elements such as pins that enable a positive-locking and/or force-locking connection between a drive shaft and an output shaft. The coupling sleeve can be a single piece or multi-piece. In this context, the term coupling spring refers to a spring that can exert a coupling force. The spring may be a coil spring. In this context, the term switching device refers in particular to a device that can actively switch between a first switching position and a second switching position. The term "first switching position" refers in this case to a switching state in which the drive shaft and the output shaft are connected in such a way that a drive torque can be transmitted. The term "second switching position" refers in this case to a switching state in which the drive shaft and output shaft are separa