Drive device for a vehicle operated by muscle power, and micro-mobility vehicle comprising this drive device

Abstract

The invention relates to a drive device for a vehicle operated by muscle power, which drive device comprises a crank device (3) for receiving muscle power and a speed modulation gear (1) for transmitting the muscle power to an output wheel (10) for driving the vehicle. The invention further relates to an electric machine (2) and to a housing (6) which can be mounted on the vehicle for accommodating at least some elements of the drive device. The speed modulation gear (1) is designed as a stepped planetary gear set comprising at least one stepped planetary gear (15), corresponding ring gears (12, 14) and an input element. The crank device (3) can be coupled to one of the ring gears (12, 14), and an output element (22) of the electric machine (2) is coupled to the input element. The speed modulation gear (1) is mounted rotatably with respect to the housing (6) so that a rotation of the electric machine (2) and a rotation of the crank device (3) can be superimposed and transmitted to the output wheel (10). The invention further relates to a micro-mobility vehicle which comprises a drive device of this kind.

Description

[0001] Drive device for a muscle-powered vehicle and micromobility vehicle with this drive device

[0002] The present invention relates to a drive device for a muscle-powered vehicle, in which a driving force for driving the vehicle is generated at least temporarily by the muscle power of a driver of the vehicle. Furthermore, the present invention relates to a vehicle equipped with such a drive device.

[0003] DE 10 2009 045 447 discloses a drive device for a two-wheeler in which a drive force introduced by muscle power can be assisted by an electric drive motor. This drive device features a planetary gear for reducing the output speed of the electric drive motor.

[0004] CN 1237520 A discloses a drive device for a muscle-powered vehicle, which can be configured as a two-wheeler. This drive device uses a transmission that allows the drive force of an electric motor and a drive force generated by the driver's muscle power to be superimposed.

[0005] A drive device for a muscle-powered vehicle is provided, wherein the drive device has a crank device for absorbing muscle power and a superposition gear for transmitting the muscle power to an output gear. A drive force for driving the vehicle is output via the output gear. Furthermore, the drive device has an electric machine and a housing mountable on the vehicle for at least partially accommodating elements of the drive device. The superposition gear is designed as a stepped planetary gear set with at least one stepped planetary gear, corresponding ring gears, and an input element. The crank device can be coupled to one of the ring gears, and an output element of the electric machine is coupled to the input element.The superposition gear is arranged rotatably with respect to the housing so that a rotation of the electric machine and a rotation of the crank device are superimposed and transmitted to the output gear.

[0006] In this context, the electric machine is designed as an electric machine for speed control, with the speed control being related to the output gear and achieved in conjunction with the superposition gear. The crank mechanism can have a crankshaft that carries corresponding crank arms on both sides. The drive force generated by muscle power can be applied to the crankshaft via the crank arms with attached pedals. In this context, the input element can be an element of the superposition gear, which is suitable for introducing a drive force from the electric machine into the superposition gear.

[0007] According to one embodiment, the stepped planetary gear can comprise a large-diameter planetary gear and a small-diameter planetary gear coupled thereto. The superposition gear can further comprise a large-diameter ring gear meshing with the large-diameter planetary gear and a small-diameter ring gear meshing with the small-diameter planetary gear.

[0008] The stepped planetary gear can have two planetary gears coupled to one another, which have different effective diameters. A planetary gear with a large diameter can be provided, the diameter of which is larger than that of the other planetary gear, the effective diameter of which is correspondingly smaller than that of the planetary gear with a large diameter. Accordingly, two ring gears can be provided, which have different effective diameters. A ring gear with a large diameter is provided, the effective diameter of which is larger than that of the other ring gear, which correspondingly has a smaller diameter than the ring gear with a large diameter. The ring gears can each have internal teeth. The internal teeth of the ring gears can mesh with corresponding external teeth of the planetary gears to transmit power.The stepped planetary gear can be mounted so that the large-diameter planetary gear and the small-diameter planetary gear rotate at the same speed. The ring gears can rotate at different speeds during operation of the superposition gear.

[0009] According to one embodiment, the superposition gearing can have a small-diameter sun gear that meshes with the large-diameter planetary gear. It can be provided that the small-diameter planetary gear meshes only with the small-diameter ring gear. The small-diameter sun gear can form the input element to which the output element of the electric machine is coupled. In this embodiment, it can be provided that the small-diameter planetary gear meshes with no other element than the small-diameter ring gear.

[0010] According to one embodiment, the superposition gearing can have a large-diameter sun gear that meshes with the small-diameter planetary gear. It can be provided that the large-diameter planetary gear meshes only with the large-diameter ring gear. The large-diameter sun gear can form the input element to which the output element of the electric machine is coupled. According to this embodiment, it can be provided that the large-diameter planetary gear meshes with no other element than the large-diameter ring gear.

[0011] According to one embodiment, the superposition gearing can have a stepped planetary carrier that holds the at least one stepped planetary gear rotatable and movable on an orbit about an axis of symmetry of the superposition gearing. The stepped planetary carrier can form the input element to which the output element of the electric machine is coupled. Provision can be made for the stepped planetary gear to mesh only with the corresponding ring gears. According to this embodiment, provision can be made for the stepped planetary gear to mesh with no elements other than the corresponding ring gears. The corresponding ring gears are, respectively, the large-diameter ring gear and the small-diameter ring gear. The stepped planetary carrier can take any shape, as long as it is suitable for holding the stepped planetary gear rotatable and, at the same time, for keeping the stepped planetary gear movable on an orbit about the axis of symmetry of the superposition gearing.The stepped planetary gear according to this embodiment can then form the input element to which the output element of the electric machine is coupled. This coupling of the output element of the electric machine and the input element designed as a stepped planetary gear allows the stepped planetary gear to be moved along its orbit.

[0012] According to one embodiment, the electric machine and the superposition gearing can be arranged coaxially with one another. In particular, it can be provided that the electric machine and the superposition gearing are arranged coaxially on an axis of symmetry, wherein the electric machine and the superposition gearing are arranged adjacent to one another in the axial direction.

[0013] According to one embodiment, a freewheel can be provided in the power transmission path between the crank mechanism and the superposition gearing, which allows power transmission between the crank mechanism and the superposition gearing only in one direction of rotation. In this case, it can be provided that in a first direction of rotation of the crank mechanism, a drive force is transmitted to the superposition gearing, while in a second direction of rotation, which is opposite to the first direction of rotation, no power can be transmitted from the crank mechanism to the superposition gearing. The freewheel can take any form as long as the aforementioned function is fulfilled.

[0014] According to one embodiment, an electric drive motor can also be provided, which can be coupled to an input element of the superposition gearing via an output element, so that the drive force of the electric drive motor can be transmitted to the output gear of the superposition gearing. The electric drive motor is provided in addition to the electric machine provided for speed control in conjunction with the superposition gearing. In one embodiment, the electric drive motor can be designed with a higher output power than the electric machine for speed control.

[0015] According to one embodiment, a reduction gear can be provided between the output element of the electric drive motor and the input element of the superposition gearing to reduce the speed output by the electric drive motor. Any type of reduction gear can be used, as long as the drive force output by the electric drive motor can be applied to the superposition gearing at a reduced speed. Due to the reduction in speed, the available torque based on the torque of the electric drive motor can be increased.

[0016] According to one embodiment, the reduction gear can comprise one of a planetary gear set and a spur gear set. It can be provided that the reduction gear has a planetary gear set that is arranged coaxially with the output element of the electric drive motor. Furthermore, it can be provided that a spur gear set with at least two spur gears is arranged. The spur gear set, which has at least two spur gears, can be used to generate an offset between the output element of the electric drive motor and the input element of the superposition gear. The spur gear set can comprise more than two spur gears, in particular three spur gears. Furthermore, it can be provided that more than one planetary gear set is arranged, wherein the planetary gear sets can be connected in series.

[0017] According to one embodiment, the electric drive motor can be arranged axially offset with respect to the superposition gearing and the electric machine. In particular, it can be provided that the electric drive motor is arranged axially offset with respect to the axis of symmetry of the superposition gearing and the electric machine for speed control. A spur gear set can be provided that is configured to compensate for the axial offset between the electric drive motor and the superposition gearing and the electric machine. This design makes it possible to provide a compact drive device.

[0018] According to one embodiment, the drive force of the electric drive machine can be applied directly to an element of the superposition gearing that carries the output gear. In particular, the drive force of the electric drive machine can be applied to the element of the superposition gearing that carries the output gear without passing through the superposition gearing. The drive force of the electric machine can be the drive force that is generated, if necessary, after passing through a reduction gear. The element of the superposition gearing that carries the output gear can be any element that is non-positively connected to the output gear. With this embodiment, the application of a drive force to the element carrying the output gear directly causes the drive force to be applied to the output gear.The element carrying the output gear can have a toothing with which an element of the electric drive motor and, if applicable, the reduction gear engages for power transmission.

[0019] According to one embodiment, the crank device can be coupled to the small-diameter ring gear. If the crank device can be coupled to the small-diameter ring gear, the drive force applied to the crank device can be applied to the small-diameter ring gear. In this case, it can be provided that the crank device is decoupled from the ring gear in predetermined operating states.

[0020] According to one embodiment, the crank device can be coupled to the large-diameter ring gear. If the crank device can be coupled to the large-diameter ring gear, the drive force applied to the crank device can be applied to the large-diameter ring gear. In this case, it can be provided that the crank device is decoupled from the ring gear in predetermined operating states. According to one embodiment, the drive force of the electric drive machine can be transmitted to the output gear of the superposition gear after passing through the superposition gear. In particular, the drive force of the electric drive machine can be applied to the element of the superposition gear carrying the output gear with the inclusion of the superposition gear.

[0021] According to one embodiment, it can be provided that the output element of the electric machine can be fixed relative to the housing via a freewheel. This embodiment ensures that the electric machine, which is provided in conjunction with the superposition gear for speed control, can be fixed so that the electric machine is held non-rotatably. This makes it possible to prevent speed control by the electric machine in conjunction with the superposition gear. The freewheel can be designed as a switchable freewheel. The function as a switchable freewheel can be brought about by an electromagnetic element, a hydraulic element or a mechanical element. The function for switching the freewheel can be carried out via an instruction from the driver, an instruction issued by a control device or in any other way.The freewheel can be designed as a direction-dependent freewheel.

[0022] The locking function can be limited to one direction of rotation. The freewheel can thus be designed as a switchable freewheel.

[0023] According to one embodiment, a control device can be provided which controls the operating state, in particular the speed and direction of rotation, of the electric machine on the basis of supplied information, so that a predetermined relationship is established between the speed of the crank device and the output gear. By controlling the speed of the electric machine, the ratio can be increased or decreased at a given speed of the crank device. Furthermore, it can be ensured that, with a variable speed of the crank device, the speed of the output gear remains constant or can be kept within a predetermined speed range by controlling the speed of the electric machine. Furthermore, it can be provided that the control device controls the direction of rotation of the electric machine, so that predetermined relationships are established between the speed of the

[0024] crank mechanism and the speed of the drive wheel.

[0025] According to one embodiment, the electric drive machine can be configured for recuperative operation, wherein the electrical energy generated during recuperative operation can be used at least partially to operate the electric machine. The recuperative operation of the electric drive machine can be brought about by rotating the electric drive machine by driving the crank mechanism. Alternatively or additionally, the recuperative operation of the electric drive machine can be brought about by rotating the electric drive machine by driving the vehicle. The electrical energy generated in this way can be used to operate the electric machine directly or indirectly via an electrical energy storage device.This embodiment ensures that speed control can be achieved by the electric machine without the need for external electrical energy supply.

[0026] According to one embodiment, an electrical energy storage device can also be provided, which provides electrical energy for operating the drive device. The electrical energy storage device can be an accumulator for storing electrical energy. The electrical energy storage device can be rechargeable via an external energy source. The electrical energy storage device can be provided so that it can be removed from the associated vehicle, which can be designed as a micromobility vehicle. A micromobility vehicle is a vehicle suitable for individual transport and can be designed, for example, as an e-bike, (S-)Pedelec, cargo bike, velomobile, or similar. A micromobility vehicle can be designed as a two-wheeled, three-wheeled, or four-wheeled vehicle.

[0027] The electrical energy storage device can further be configured such that, in cooperation with the control device, it can store electrical energy generated during recuperative operation of the electric drive motor. The drive device described above can be provided on a vehicle that is at least temporarily powered by muscle power. The vehicle can be any micromobility vehicle suitable for muscle power operation, such as a two-wheeler, a three-wheeler, a cargo bike, a hand-operated vehicle, and other suitable vehicle configurations.

[0028] According to a further aspect, a micromobility vehicle with at least two wheels is provided, which has a drive device with one or more of the features described above. The output gear of the drive device is coupled to one of the wheels for driving the micromobility vehicle. The output gear can be coupled to one of the wheels for driving the micromobility vehicle via a power transmission element. The micromobility vehicle can further comprise an electrical energy storage device configured to output and receive electrical energy for operating the drive device. Furthermore, the micromobility vehicle can comprise a control device configured to operate the drive device.

[0029] Fig. 1 is a schematic view of a drive device for a human-powered vehicle according to a first embodiment;

[0030] Fig. 2 is a schematic view of a drive device for a human-powered vehicle according to a second embodiment;

[0031] Fig. 3 is a schematic view of a drive device for a human-powered vehicle according to a third embodiment;

[0032] Fig. 4 is a schematic view of a drive device for a muscle-powered vehicle, which is a modification of the embodiment of

[0033] Fig. 2; Fig. 5 is a schematic view of a drive device for a human-powered vehicle, illustrating a modification of the embodiment of Fig. 1;

[0034] Fig. 6 is a schematic view of a drive device for a human-powered vehicle according to a fourth embodiment;

[0035] Fig. 7 is a schematic view of a drive device for a human-powered vehicle according to a fifth embodiment;

[0036] In the following, embodiments of the proposed drive device for a muscle-powered vehicle are described with reference to the drawings.

[0037] Fig. 1 shows a schematic view of a drive device for a human-powered vehicle according to a first embodiment. As can be seen in Fig. 1, the drive device comprises a superposition drive 1, an electric motor 2, which serves to control the speed, and a crank device 3. Additionally, a control device 4 and an electrical energy storage device 5 are provided. The aforementioned components of the drive device and their mode of operation are explained below in their application to a micromobility vehicle designed as a two-wheeled vehicle.

[0038] The superposition gear 1, as can be seen in Fig. 1, has an output gear 10 on the right-hand side. In the present embodiment, the output gear 10 is designed as a sprocket that is connected to a rear wheel of a two-wheeler for power transmission via a drive chain. The output gear 10 is connected to a ring gear carrier 11 via a hollow shaft element. The rotation of the ring gear carrier 11 is transmitted directly to the output gear 10. A ring gear 12 is provided on the ring gear carrier 11. Extending coaxially through the output gear 10 is a crank device 3 that has a crankshaft 30 on which respective crank arms 31, 32 are provided on the left and right sides. The alignment of the crank arms 31, 32 with respect to the crankshaft 30 is offset by 180°. Pedals are provided at the end of the crank arms 31, 32. A driving force can be applied to the crankshaft 30 by the driver of the two-wheeler via the pedals and the crank arms 31, 32.

[0039] In the present embodiment, a freewheel 16 is provided on the crankshaft 30. The freewheel 16 is coupled to the crankshaft 30 on the one hand and to a ring gear carrier 13 on the other. The freewheel 16 causes rotation of the crankshaft 30 relative to the ring gear carrier 13 in one direction to be transmitted to the ring gear carrier 13, while upon rotation of the crankshaft 30 relative to the ring gear carrier 13 in the opposite direction, no force is transmitted to the ring gear carrier 13. The ring gear carrier 13 carries a ring gear 14.

[0040] The ring gear 12 provided on another ring gear carrier 11 is a large-diameter ring gear, while the ring gear 14 provided on the ring gear carrier 13 is a small-diameter ring gear. In particular, the ring gear 12 has a larger effective diameter than the ring gear 14.

[0041] A plurality of stepped planetary gears 15 are provided in the superposition gear 1. In the present embodiment, three identically constructed stepped planetary gears 15 are provided around the circumference of the axis of symmetry of the superposition gear 1 formed by the crankshaft 30. Only one stepped planetary gear 15 is explained below, and the construction of the other stepped planetary gears is correspondingly identical. The stepped planetary gear 15 has a planetary gear 151 with a large diameter and a planetary gear 152 with a small diameter. The planetary gears 151, 152 are rigidly coupled to one another via a stepped planetary axle 153. The stepped planetary axle 153 is rotatably held by a stepped planetary carrier 154.

[0042] The stepped planetary gears 15 provided in the superposition gear 1 are each rotatable by the stepped planetary carrier 154 and held on a common orbit around the axis of symmetry of the superposition gear 1. The toothing of the large-diameter ring gear 12 engages with the toothing of the large-diameter planetary gear 151, while the toothing of the small-diameter ring gear 14 engages with the toothing of the small-diameter planetary gear 152. In the present embodiment, the superposition gear 1 has a sun gear 17. The toothing of the sun gear 17 engages with the toothing of the large-diameter planetary gear 151. The sun gear 17 is designed as a small-diameter sun gear and, in the present embodiment, is connected to an output element 22, which is described elsewhere.

[0043] In this way, the superposition gear 1 is constructed as a stepped planetary gear set, in which a drive force can be input from the crank mechanism 3 and from the output element 22 coupled to the small-diameter sun gear 17. In the superposition gear 1 according to the present embodiment, the drive force can be output via the output gear 10. In the present embodiment, the small-diameter sun gear 17 serves as the input element.

[0044] In Fig. 1, an electric machine 2 is shown on the left side of the superposition gear 1. The electric machine 2 has a symmetrical design and is constructed symmetrically to the crankshaft 30. The crankshaft 30 extends through the center of the electric machine 2. The electric machine 2 has a rotor 20 that is rotatably mounted. Furthermore, the electric machine 2 has a stator 21 that is non-rotatably mounted on a housing 6. The rotor 20 is connected to the output element 22. Thus, rotation of the electric machine 2 can be transmitted via the output element 22 to the small-diameter sun gear 17.

[0045] As can be seen in Fig. 1, the controller 4 is connected to the electric machine 2. In the present embodiment, the electric machine 2 is operated by electrical energy stored in the electrical energy storage device 5. The controller 4 controls the speed and direction of rotation of the electric machine 2 so that the appropriate rotation can be initiated via the small-diameter sun gear 17 as the input element of the superposition gear. In the present embodiment, the controller 4 is supplied with signals or information input by a rider of the two-wheeler. The function of the drive device according to the first embodiment shown in Fig. 1 is described below.

[0046] In an operating state in which the electric machine 2 is not supplied with electrical energy, the rider of the two-wheeler can drive the crank device 3 via the pedal cranks to move the two-wheeler forward. The drive force is transmitted from the crank device 3 via the crankshaft 30, the freewheel 16, and the ring gear carrier 13 to the small-diameter ring gear 14. This causes the stepped planetary gear 15 to rotate via the small-diameter planetary gear 152 and move it in an orbit. Through the rotation of the stepped planetary gear 15 and the orbit of the stepped planetary gear 15, the ring gear carrier 11, and thus the output gear 10, is rotated via the meshing of the large-diameter planetary gear 151 with the large-diameter ring gear 12.The ratios of the toothings of the individual planetary gears and ring gears result in a predetermined transmission ratio between the rotational speed of the crankshaft 30 and the output gear 10. Due to the coupling of the provided stepped planetary gears 15 to the planetary carrier, the movement sequence described above applies to each of the stepped planetary carriers 15.

[0047] In a further operating state, the electric machine 2 is supplied with electrical energy, causing it to rotate. The electric machine 2 can be driven in a direction of rotation that corresponds to the direction in which the crankshaft 30 is rotated. As a result, the rotation of the output element 22 of the electric machine 2 is transmitted via the small-diameter sun gear 17 to the stepped planetary gear 15. In this case, the rotational speed of the electric machine 2 and the rotational speed of the crankshaft 30 are superimposed on one another. As a result, the speed ratio and thus the transmission ratio between the crankshaft 30 and the output gear 10 can be adjusted depending on the rotational speed of the electric machine 2.

[0048] In a further operating state, the electric machine 2 can be rotated in the opposite direction to that in which the crankshaft 30 rotates. In this case, too, the rotational speed of the electric machine 2 and the rotational speed of the crankshaft 30 are superimposed, resulting in a variable transmission ratio between the rotational speed of the crankshaft 30 and the output gear 10.

[0049] In the present embodiment, the driver can specify a gear ratio between the crankshaft 30 and the output gear 10 via the control device 4 using an input element (not shown). The control device 4 then controls the direction of rotation and the speed of the electric machine 2 based on the input from the driver of the two-wheeler, so that the desired gear ratio between the crankshaft 30 and the output gear 10 is established. During operation of the output device, the superposition gear 1 rotates about its axis. In particular, the superposition gear is not rotationally fixedly supported relative to the housing 6. Furthermore, in this embodiment, the small-diameter planetary gear 152 engages only with the small-diameter ring gear 14 via its toothing.

[0050] In a modified embodiment, corresponding rotational speed sensors and speed sensors are provided, the signals of which are fed into the control device 4. Based on the signals, the control device 4 can determine an optimal gear ratio between the crankshaft 30 and the electric machine 2 and control the electric machine 2 accordingly. In this case, a continuously variable automatic gear ratio control for the drive device is achieved.

[0051] If the rider of the two-wheeler stops driving the crankshaft 30 via the pedal cranks, the superposition gear 1 can continue to rotate due to the arrangement of the freewheel 16. Furthermore, it is possible for the rider to rotate the crankshaft 30 backward via the pedal cranks, in which case no drive force is introduced into the superposition gear 1 due to the arrangement of the freewheel 16. A drive device according to a second embodiment is described below based on the illustration in Fig. 2. For simplicity, only the differences between the drive device of Fig. 2 and the drive device of Fig. 1 are explained. As can be seen in Fig. 2, an output element 22 is provided on the electric machine 2. In contrast to the design of Fig. 1, the output element 22 is designed with a sun gear 18 with a large diameter, which engages with the planet gear 152 with a small diameter.In this embodiment, the large diameter planetary gear 151 is only in engagement with the large diameter ring gear 12.

[0052] The operation and advantages of the second embodiment shown in Fig. 2 are the same as those of Fig. 1. With the structure shown in Fig. 2, an alternative transmission ratio of the superposition gear can be provided.

[0053] In the following, a drive device according to a third embodiment is described on the basis of the illustration in Fig. 3. In the following, only differences between the drive device of Fig.

[0054] 3 and that of Fig. 1.

[0055] As in the drive device of Fig. 1, the electric machine 2 has the output element 22. In the exemplary embodiment of Fig. 3, the output element 22 of the electric machine 2 is connected to a stepped planetary carrier 19, in contrast to the structure of Fig. 1. The stepped planetary carrier 19 is connected to the stepped planetary carrier 154, which holds the stepped planetary gears 15 rotatable and movable on an orbit. Thus, a rotation of the electric machine 2 is transmitted via the output element 22 to the stepped planetary carrier 19, so that the stepped planetary gears 15 are moved on an orbit around the axis of symmetry of the superposition gear. As can be seen in Fig. 3, the large-diameter planetary gear 151 meshes only with the large-diameter ring gear 12, while the small-diameter planetary gear 152 meshes only with the small-diameter ring gear 14. A sun gear is in the drive device of the embodiment of Fig.3 is not provided. The function and advantages of the drive device of Fig. 3 are the same as those described with reference to Fig. 1. With the structure shown in Fig. 3, alternative gear ratios can be achieved between the electric machine 2, the superposition gear, the output gear 10, and the crankshaft 30.

[0056] Fig. 4 represents a modification of the embodiment shown in Fig. 2. In contrast to the structure of the drive device of Fig. 2, in the drive device of Fig. 4 the orientation of the stepped planetary gear 15 is reversed. In particular, in this embodiment the positions of the large diameter planetary gear 151 and the small diameter planetary gear 152 are reversed. As in the embodiment of Fig. 2, the large diameter sun gear 18 meshes with the small diameter planetary gear 152. Furthermore, the output gear 10 is connected to the small diameter ring gear 14, while the crankshaft 30 is connectable to the large diameter ring gear 12. The further structure of the drive device shown in Fig. 4 corresponds to that of the drive device shown in Fig. 2. With this structure an alternative gear ratio can be achieved.

[0057] Fig. 5 represents a modification of the embodiment shown in Fig. 1. In contrast to the structure of the drive device of Fig. 1, in the drive device of Fig. 5 the orientation of the stepped planetary gear 15 is reversed. In particular, in this embodiment the positions of the large diameter planetary gear 151 and the small diameter planetary gear 152 are reversed. As in the embodiment of Fig. 1, the small diameter sun gear 17 meshes with the large diameter planetary gear 151. Furthermore, the output gear 10 is connected to the small diameter ring gear 14, while the crankshaft 30 is connectable to the large diameter ring gear 12. The further structure of the drive device shown in Fig. 5 corresponds to that of the drive device shown in Fig. 1. With this structure an alternative gear ratio can be achieved.A drive device according to a fourth embodiment will be explained below with reference to Fig. 6. As can be seen in Fig. 6, in addition to the structure shown in Fig. 1, the drive device has an electric drive machine 7, which is provided in addition to the electric machine 2. Furthermore, a reduction gear 8 is shown in the embodiment of Fig. 6. It should be noted that the structure of the electric machine 2, the superposition gear 1 and the crank device 3 is the same as the structure of the drive device of Fig. 1. However, the embodiment of Fig. 6 can also be formed with the embodiments according to Figs. 2 and 3 and the additionally described modifications shown in Figs. 4 and 5.

[0058] The electric drive motor 7, which is provided in addition to the electric machine 2, is offset in the present embodiment axially parallel to the axis of symmetry of the electric machine 2 and the superposition gear 1. The electric drive motor 7 has a rotor 70 that is rotatably mounted. Furthermore, the electric drive motor 7 has a stator 71 that is fastened to the housing 6 of the drive device. An output element 72 is provided on the rotor 70 of the electric drive motor 7. The output element 72 is connected to a planetary gear set 82, which serves to reduce the speed at the output element 72 based on the speed of the electric drive motor 7.

[0059] The planetary gear set 82 has an output element that is connected on the input side to a spur gear set 81. The spur gear set 81 according to the present embodiment has a gear provided on the output element of the planetary gear set 82. This gear engages with an intermediate gear, which in turn engages with an input element 83 of the superposition gearing. The input element 83 of the superposition gearing 1 is designed as a toothing on the circumference of the ring gear carrier 11. Thus, in the present embodiment, the planetary gear set 82 is provided to reduce the speed of the electric drive motor 7, and the spur gear set 81 is also provided to compensate for the axially parallel offset of the electric drive motor 7 with respect to the axis of symmetry of the electric machine 2 and the superposition gearing 1.

[0060] The electric drive motor 7 can be driven via the control device 4 and using electrical energy stored in the electrical energy storage device 5. In an operating state in which the rider of the two-wheeler drives the crankshaft 30 via the pedal cranks to drive the two-wheeler forward, the superposition gear 1, in particular the ring gear carrier 11 with the input element 83 attached thereto, rotates depending on the operating state of the electric machine 2. According to a specification from the rider of the two-wheeler, the electric drive motor 7 can be driven so that the drive force of the electric drive motor 7 is applied to the input element 83 of the superposition gear 1. Thus, the drive force applied by the rider of the two-wheeler via the pedal cranks can be supplemented by the drive force of the electric drive motor. The drive shown in Fig.The system shown in Figure 6 thus represents an electrically assisted drive, as used in pedelecs or e-bikes, i.e. bicycles with electrical assistance.

[0061] In addition, since the superposition gear 1 and the electric machine 2, which have already been described with reference to Fig. 1, are provided, in this embodiment, the assist function of the electric drive machine 7 is combined with the variable gear ratio function by the superposition gear 1 and the electric machine 2.

[0062] A drive device according to a fifth embodiment is explained with reference to the illustration of Fig. 7. In the following, only differences between the structure of the drive device according to Fig. 6 and the structure according to Fig. 7 are described.

[0063] In the embodiment according to Fig. 7, the drive device has the electric drive machine 7 and the reduction gear 8. The electric drive machine 7 is constructed similarly to that of Fig. 6, and the reduction gear 8 is also constructed similarly to that in Fig. 6. The structure of the drive device in Fig. 7 differs from the structure of the drive device according to Fig. 6 in that the crankshaft 30 of the crank device 3 is configured to transmit the rotation to the ring gear carrier 11. This causes the rotation of the crankshaft 30 to be transmitted to the large-diameter ring gear 12. The rotation of the large-diameter ring gear 12 is transmitted in the present embodiment to the large-diameter planet gear 151. The large-diameter planet gear 151 meshes with the small-diameter sun gear 17, which is connected to the electric machine 2.The small-diameter planetary gear 152 meshes with the small-diameter ring gear 14. The small-diameter ring gear 14 is coupled to the output gear 10 via the ring gear carrier 13.

[0064] In the embodiment shown in Fig. 7, a freewheel 162 is further provided, which can limit the rotation of the electric machine 2 relative to the housing 6 in at least one direction of rotation. In the present embodiment, the freewheel 162 is designed as a switchable freewheel. Thus, the rotation of the electric machine 2 can advantageously be prevented in predetermined operating states. In an embodiment deviating from this, a non-switchable freewheel 162 is provided between the crankshaft 30 and the output gear 10, which only allows power transmission between the crankshaft 30 and the output gear 10 in one direction of rotation. Furthermore, in the present embodiment, a freewheel 163 is provided between the crankshaft 30 and the ring gear carrier 11, which only allows the rotation of the crankshaft 30 to be transmitted to the freewheel carrier 11 in one direction of rotation.

[0065] The embodiments shown in Fig. 6 and Fig. 7 thus provide an electrically assisted drive device for a two-wheeler with the function of variably adjusting the gear ratio between crank speed and output wheel speed. The operation of the electric drive motor 7 and the electric machine 2, which is used for speed control, can be controlled by the control device 4. The electrical energy for operating the drive device can be obtained from the electrical energy storage device 5. In a further embodiment, the electric drive motor 7 can be used for recuperative operation. In this recuperative operation, the electric drive motor 7 can be driven while the crankshaft 30 is driven by the rider of the two-wheeler.The recuperation of the electric drive motor 7 achieved with this drive can be used to generate energy. This energy can, in turn, be used to operate the electric motor 2, which is used for speed control. This makes it possible to enable battery-neutral operation.

[0066] With the drive device according to Fig. 6 and Fig. 7, a recuperative braking mode can also be implemented. For this purpose, the electric drive motor 7 can be placed into a recuperation mode by the control device 4 using known means, so that a braking torque is generated at the drive device. The electrical energy generated by the recuperation operation of the electric drive motor 7 can be stored in the battery or used for other purposes.

[0067] Reference symbol

[0068] Superposition gear

[0069] Output gear

[0070] Ring gear carrier

[0071] Large diameter ring gear

[0072] Ring gear carrier

[0073] Small diameter ring gear

[0074] Stepped planetary gear 1 Large diameter planetary gear 2 Small diameter planetary gear 3 Stepped planetary axle 4 Stepped planetary carrier

[0075] Freewheel 1 Freewheel 2 Freewheel 3 Freewheel

[0076] Small diameter sun gear

[0077] Large diameter sun gear

[0078] Stepped planetary gear electric machine for speed control

[0079] rotor

[0080] stator

[0081] Output element

[0082] Crank device

[0083] Crankshaft, 32 crank arm

[0084] Control device

[0085] Electrical energy storage device

[0086] Housing electric drive motor

[0087] rotor

[0088] stator

[0089] Output element Reduction gear Spur gear set Planetary gear set Input element Superposition gear

Claims

Patent claims 1. Drive device for a muscle-powered vehicle, wherein the The drive device comprises a crank device (3) for receiving muscle force, a superimposed transmission (1) for transmitting the muscle force to an output gear (10) via which a driving force is delivered to propel the vehicle, an electric machine (2) and a housing (6) mountable on the vehicle for at least partially accommodating elements of the drive device, wherein the superimposed transmission (1) is designed as a stepped planetary gear set with at least one stepped planetary gear (15), corresponding ring gears (12, 14) and an input element (17; 18; 19), wherein the crank device (3) can be coupled to one of the ring gears (12, 14) and an output element (22) of the electric machine (2) can be coupled to the input element (17; 18;19) is coupled, wherein the superimposed transmission (1 ) is rotatably arranged with respect to the housing (6), so that a rotation of the electric machine (2) and a rotation of the crank mechanism (3) are superimposed and transmitted to the output wheel (10).

2. Drive device according to claim 1, characterized in that the stepped planetary gear (15) has a planet gear (151) with a large diameter and a planet gear (152) coupled thereto with a small diameter, wherein the superimposed gear (1) further comprises a ring gear (12) with a large diameter which engages with the planet gear (151) with a large diameter, and a ring gear (14) with a small diameter which engages with the planet gear (152) with a small diameter.

3. Drive device according to claim 2, characterized in that the superimposed transmission (1) has a sun gear (17) with a small diameter which engages with the planet gear (151) with a large diameter and wherein the planet gear (152) with a small diameter engages only with the ring gear (14) with a small diameter, wherein the sun gear (17) with a small diameter forms the input element (17) with which the output element (22) of the electric machine (2) is coupled.

4. Drive device according to claim 2, characterized in that the superimposed transmission (1 ) has a sun gear (18) with a large diameter which engages with the planet gear (152) with a small diameter and wherein the planet gear (151 ) with a large diameter engages only with the ring gear (12) with a large diameter, wherein the sun gear (18) with a large diameter forms the input element (18) with which the output element (22) of the electric machine (2) is coupled.

5. Drive device according to claim 2, characterized in that the superposition gear (1 ) has a stepped planetary web (19) which holds the at least one stepped planetary wheel (15) rotatably and movable on a orbit about an axis of symmetry of the superposition gear (1 ), wherein the stepped planetary web (19) forms the input element (19) with which the output element (22) of the electric machine (2) is coupled, wherein the stepped planetary wheel (15) engages only with the corresponding ring gears (12, 14).

6. Drive device according to one of the preceding claims, characterized in that the electric machine (2) and the superimposed transmission (1) are arranged coaxially to each other.

7. Drive device according to one of the preceding claims, characterized in that a freewheel is provided in the power transmission path between the crank device (3) and the superimposed gear (1), which allows power transmission only in one direction of rotation.

8. Drive device according to one of the preceding claims, characterized in that an electric drive machine (7) is further provided which is coupled via an output element (72) to an input element (83) of the superimposed transmission (1) so that the drive force of the electric drive machine (7) is transmitted to the output wheel (10) of the superimposed transmission (1).

9. Drive device according to claim 8, characterized in that a reduction gear (8) is provided between the output element (72) of the electric drive machine and the input element (83) of the superimposed gear (1) to reduce the rotational speed output by the electric drive machine (7).

10. Drive device according to claim 9, characterized in that the reduction gear (8) comprises a planetary gear set (82) and a spur gear set (81).

11. Drive device according to one of claims 8-10, characterized in that the electric drive machine (7) is arranged axially offset with respect to the superimposed gear unit (1) and the electric machine (2).

12. Drive device according to one of claims 8-11, characterized in that the drive force of the electric drive machine (7) is applied directly to an element of the superimposed transmission (1) that supports the output wheel (10).

13. Drive device according to one of the preceding claims, characterized in that the crank device (3) can be coupled to the small diameter ring gear (14) or to the large diameter ring gear (12).

14. Drive device according to one of claims 8-11, characterized in that the drive force of the electric drive machine (7) is transferred to the output wheel (10) of the superimposed transmission (1) after passing through the superimposed transmission (1).

15. Drive device according to one of the preceding claims, characterized in that the output element (22) of the electric machine (2) can be fixed relative to the housing (6) via a freewheel.

16. Drive device according to one of the preceding claims, characterized in that a control device (4) is provided which controls the operating state, in particular speed and direction of rotation, of the electric machine (2) on the basis of supplied information, so that a predetermined ratio is established between the speed of the crank device (3) and the driven wheel (10).

17. Drive device according to one of claims 8-16, characterized in that the electric drive machine (7) is configured for recuperative operation, wherein the electrical energy generated in recuperative operation is used at least partially for the operation of the electric machine (2).

18. Drive device according to one of the preceding claims, characterized in that an electrical energy storage device (5) is further provided which provides electrical energy for the operation of the drive device.

19. Micromobility vehicle with at least two wheels and a drive unit according to one of the preceding claims, wherein the driven wheel (10) is coupled to one of the wheels via a power transmission element for driving the micromobility vehicle.

Images