Device for a muscle-powered vehicle

Abstract

The invention relates to a device (1) for a muscle-powered vehicle (30), comprising an electric machine (2) having a stator (3) and a rotor (4), an eccentric gearing (5) which is arranged coaxially to the electric machine (2), a pedal crankshaft (6) which is arranged on a common rotational axis (7) with the electric machine (2) and the eccentric gearing (5), and a housing (8) for receiving the electric machine (2), the eccentric gearing (5) and substantially also the pedal crankshaft (6), wherein the eccentric gearing (5) has a planetary carrier (9) having a plurality of carrier bolts (10) and at least one planetary roll (11.1, 11.2) arranged in a rotatable manner on the respective carrier bolt (10), an at least one eccentric gear (12.1, 12.2) having a plurality of driver openings and a central eccentric receiving opening, a ring gear toothing (13) and an eccentric shaft (14), wherein in the torque flow between the pedal crankshaft (6) and the electric machine (2) a damper unit (15) is arranged, comprising a spring channel (16) and a plurality of springs (17) arranged in the spring channel (16).

Description

[0001] Device for a muscle-powered vehicle

[0002] The invention relates to a device for a human-powered vehicle, the device comprising an electric motor and an eccentric gear. Furthermore, the invention relates to a human-powered vehicle with such a device. The human-powered vehicle is preferably an e-bike.

[0003] For example, DE 102021 119 145 A1 discloses a drive arrangement for a human-powered vehicle, comprising a generator module for generating electrical energy for a drive module. The generator module comprises a generator that can be driven by a vehicle user using pedal power, and a transmission device for transmitting the pedal power to the generator. The drive module serves to generate an electrical drive torque, wherein the drive module comprises an electric motor that can be connected to a drive wheel of the vehicle for driving purposes, and a further transmission device for transmitting the electrical drive torque to the drive wheel. The transmission device of the generator module and the further transmission device of the drive module are essentially identical in construction, each designed as an eccentric gear.The eccentric gear comprises an eccentric gear carrier with several carrier pins, at least one eccentric gear with several drive openings and a central eccentric receiving opening, a ring gear section, and an eccentric shaft. Each carrier pin engages in one of the drive openings, the eccentric shaft engages in the central eccentric receiving opening, and the eccentric gear runs in the ring gear section.

[0004] The object of the present invention is to provide a device for a human-powered vehicle, in particular to reduce oscillations and vibrations during operation of the device. This object is achieved by the subject matter of patent claim 1. Preferred embodiments can be found in the dependent claims.

[0005] A device according to the invention for a human-powered vehicle comprises an electric machine with a stator and a rotor, an eccentric gear arranged coaxially with the electric machine, a pedal crankshaft arranged on a common axis of rotation with the electric machine and the eccentric gear, and a housing for accommodating the electric machine, the eccentric gear and essentially also the pedal crankshaft, wherein the eccentric gear has a planetary carrier with a plurality of carrier bolts and at least one planetary roller rotatably arranged on the respective carrier bolt, at least one eccentric wheel with a plurality of driving openings and a central eccentric receiving opening, a ring gear toothing and an eccentric shaft, wherein a damper unit is arranged in the torque flow between the pedal crankshaft and the electric machine, comprising a spring channel and a plurality of springs arranged in the spring channel.

[0006] For example, the device is designed as a generator module for a human-powered vehicle, wherein the human-powered vehicle is an e-bike. Preferably, the human-powered vehicle further comprises an electric motor, wherein the electrical energy required for driving the electric motor is generated at least partially by the user driving the generator module. Thus, during operation of the human-powered vehicle, the generator module is driven by the user, with the torque flowing from the pedal crankshaft via the eccentric gear to the electric machine. The pedal crankshaft is connected to pedals via cranks, with the user inputting the output power via the pedals. The eccentric gear increases an input-side rotational speed of the pedal crankshaft and thus acts as a transmission gear.In particular, the eccentric shaft of the eccentric gear is provided as an output shaft and is connected in a rotationally fixed manner to the rotor of the electric machine.

[0007] The respective carrier pin of the eccentric gear is guided through a driving opening on the at least one eccentric gear. The respective planetary roller, which is arranged on the respective carrier pin, is designed to at least partially engage in the respective driving opening, wherein the eccentric shaft engages in the respective eccentric receiving opening and the at least one eccentric gear runs in the ring gear toothing. According to a preferred embodiment, a first planetary roller and a second planetary roller are arranged on each carrier pin, wherein a first eccentric gear and a second eccentric gear are arranged on eccentrics on the eccentric shaft that are rotated by 180° to one another.The respective first planetary roller is designed to come into contact at least partially, in particular temporarily, in the respective driving opening on the first eccentric wheel, wherein the respective second planetary roller is designed to come into contact at least partially, in particular temporarily, in the respective driving opening on the second eccentric wheel. This is because, during operation of the eccentric gear, the eccentric wheels rotate, in particular offset by 180° to one another, wherein the respective first and second planetary rollers are designed to rotate and alternately carry loads. The respective driving opening is cylindrical and provided as a raceway for the respective planetary roller. In particular, the eccentric shaft engages in the eccentric receiving opening of the respective eccentric wheel, wherein the respective eccentric wheel runs in the ring gear toothing.

[0008] Eccentric gears inherently have play, particularly between the planetary rollers and the drive openings. This play in the gear can generate disruptive excitations and vibrations on the crankshaft and thus on the respective pedal. The damper unit reduces oscillations and vibrations during operation of the device. The springs of the damper unit are designed to dampen oscillations and vibrations, with the spring channel designed to accommodate the springs. A spring is an elastic damping element capable of elastic deformation to dampen oscillations and vibrations.

[0009] According to a preferred embodiment, the damper unit is arranged in the torque flow between the pedal crankshaft and the planetary gear. The damper unit is preferably arranged axially between the housing and the eccentric gear. In particular, the spring channel is connected to the pedal crankshaft in a rotationally fixed manner and is provided as the damper input. The planetary gear preferably dampens vibrations via the springs of the damper unit, thus is not rigidly connected to the damper unit, and serves in particular as the damper output. Alternatively, the damper unit can be arranged between the eccentric gear and the electric motor. Furthermore, the damper unit can be arranged radially above the eccentric gear.

[0010] In particular, the springs of the damper unit are preloaded to ensure that the crankshaft and thus also the pedals are connected to the eccentric gear as rigidly as possible, preferably without rattling. Vibration damping of the damper unit occurs once the preload of the springs has been overcome, i.e., as soon as the springs are at least partially elastically deformed, in particular compressed. The springs preferably have a clearance angle so that the damper unit dampens vibrations even at low torques.

[0011] According to a preferred embodiment, at least one actuating element is arranged on the planetary carrier for each spring of the damper unit. The respective spring can be actuated, in particular compressed, via the respective actuating element. The actuating elements are preferably integrally connected to the planetary carrier. For example, the actuating elements extend from the planetary carrier in the axial direction to the spring channel, with the springs resting against the actuating elements at least on one side in the circumferential direction.

[0012] According to a preferred embodiment, the damper unit has two to six springs that rest on stop elements in the spring channel, with at least one spring being designed as a compression spring. For example, at least one spring is designed as a helical compression spring. In particular, at least one spring is designed as an arc spring. A arc spring is an arc-shaped helical compression spring with a circular arc-shaped helical axis. For example, the spring channel of the damper unit has two to six arc-shaped sub-sections, with each arc-shaped sub-section being designed to accommodate a spring. The damper unit preferably has exactly four springs. In particular, the number of stop elements on the spring channel corresponds to the number of springs in the spring channel, with a spring being arranged between two stop elements in each case.In particular, all stop elements are arranged on a first circular path which has a smaller diameter than a second circular path on which all actuating elements are arranged. The respective stop element is preferably connected in one piece to the respective spring channel. For example, the stop elements extend from the spring channel in the axial direction to the planet carrier, wherein the springs come into contact with the stop elements in the circumferential direction at least on one side. According to a preferred embodiment, the spring channel is connected in a rotationally fixed manner to the pedal crankshaft. For example, the spring channel, which is configured as a damper input, is formed in one piece with the pedal hub and / or the pedal crankshaft. Alternatively, the spring channel is connected in a rotationally fixed manner to the pedal hub and / or the pedal crankshaft, in particular by welding, riveting, screwing, or plugging. The spring channel is preferably fastened to the planet carrier with the springs.Alternatively, the spring channel is formed in one piece on the planet carrier, in which case the actuating elements are arranged on the pedal hub, in particular are connected in one piece to the pedal hub or the pedal crankshaft.

[0013] According to a preferred embodiment, the planet carrier is supported at least on one side by a single bearing or on both sides by exactly two bearings. For example, the single bearing is arranged radially between the planet carrier and the pedal crankshaft. Preferably, two bearings are provided for supporting the planet carrier, wherein these bearings are arranged on both sides next to the eccentric gear and rotatably support the planet carrier relative to the pedal crankshaft and the eccentric shaft. In particular, the planet carrier is mounted radially on the outside against the housing. Furthermore, the planet carrier is mounted via the springs in the damper unit.

[0014] The damper unit preferably has a torsion angle of at least 5° to a maximum of 35°. The torsion angle of the damper unit is determined by the spring rate and the stop torque. It is advantageous to keep the torsion angle small to create a pleasant feeling for the user while cycling. The torsion angle is preferably at least 8° to a maximum of 20°. To make the damper unit softer and, in particular, to accommodate partial loads, a torsion angle of 25°, 30°, or 35° can be provided.

[0015] According to a preferred embodiment, the damper unit is designed with at least one or more stages of damping in a torque range of at least 20 Nm to a maximum of 180 Nm. The torque can be detected using torque sensors or a torque transducer. At an applied torque of less than 20 Nm, the damper unit therefore has no damping effect because the torque is too small to actuate the springs, in particular to compress them. At an applied torque of greater than 180 Nm, the damper unit has no damping effect because the torque is so great that the springs are fully actuated, in particular compressed, and the spring travel is thus fully exhausted. In other words, at an applied torque of more than 180 Nm, the damper unit is in the locked state, so that no damping effect occurs.Therefore, the damper unit preferably has an operating range of at least 20 Nm to a maximum of 180 Nm. The maximum operating range of the damper unit is preferably 160 Nm. In particular, the maximum operating range of the damper unit can be 40 Nm or 80 Nm if the damper unit is designed for a partial load torque. For example, the damper unit can be designed for multi-stage operation, with a first operating range of the damper unit having, for example, 40 Nm to 80 Nm, while at least a second operating range of the damper unit has a larger torque range and thus also greater rigidity. This can, in particular, increase comfort for the user.

[0016] Single-stage damping means that the damper unit essentially has a single damping effect in the torque range. Multi-stage damping means that the damper unit has several different damping effects in the torque range.

[0017] According to a preferred embodiment, the multi-stage damping damper unit has different spring lengths and / or different spring types. For example, initially only half or one-third of the springs are used for damping. Only after a defined angle of rotation or above a defined torque are the other springs also used. For example, the damper unit has a soft first stage, which is created, for example, by soft springs, whereas the second stage of the damper unit, which follows from a defined angle of rotation or above a defined torque, has a higher stiffness, which is created, for example, by a spring designed as a rubber stop or a very stiff, short spring.

[0018] A human-powered vehicle according to the invention comprises a device according to the invention. In particular, the human-powered vehicle is designed as an e-bike and additionally has a drive motor, wherein the device is configured as a generator module for the drive motor.

[0019] Further measures improving the invention are described in more detail below together with the description of a preferred embodiment of the invention with reference to the figures.

[0020] Figure 1 is a schematic sectional view illustrating a device according to the invention,

[0021] Figure 2 is a schematic perspective view of a damper unit of the device according to the invention,

[0022] Figure 3 is a schematic perspective view of a planet carrier of the device according to the invention,

[0023] Figure 4 is a schematic perspective sectional view of the damper unit with planet carrier in a partially assembled state, and

[0024] Figure 5 is a schematic representation of a muscle-powered vehicle with a device according to the invention.

[0025] Figure 1 shows a device 1, comprising an electric machine 2 with a stator 3 and a rotor 4 as well as an eccentric gear 5, which are arranged coaxially to one another in a common housing 8. The electric machine 2 and the eccentric gear 5 are arranged axially adjacent to one another, with the pedal crankshaft 6 being guided axially through the electric machine 2 and the eccentric gear 5. The structure of the device 1 is thereby particularly compact. The device 1 further comprises a pedal crankshaft 6, which is arranged on a common axis of rotation 7 with the electric machine 2 and the eccentric gear 5, and power electronics 40 for controlling the electric machine 2. The electric machine 2 is arranged axially between the eccentric gear 5 and the power electronics 40 in the common housing 8.The housing 8 thus accommodates the electric motor 2 including the power electronics 40, the eccentric gear 5, and the pedal crankshaft 6, with a respective pedal hub 41, 42 rotatably mounted on both sides of the pedal crankshaft 6. The first pedal hub 41 is rotatably mounted on the housing 8 via a bearing 20.4. The second pedal hub 42 is rotatably mounted on a housing cover 8.1 via a bearing 20.3. The device 1 is intended for a human-powered vehicle 30, which is shown in Figure 5.

[0026] The eccentric gear 5 comprises a planetary carrier 9 with a plurality of carrier bolts 10, of which only two carrier bolts 10 are shown here, and two planetary rollers 11.1, 11.2 rotatably arranged on the respective carrier bolt 10. The planetary rollers 11.1, 11.2 are rotatably mounted on the carrier bolt 10 via respective bearings and are axially secured by a disk fixed to the front side by means of a screw. The disk is also provided for supporting the planetary carrier 9 via a bearing 20.2 on an eccentric shaft 14 of the eccentric gear 5. The eccentric gear 5 further comprises a ring gear toothing 13 and two eccentric wheels 12.1, 12.2, each with a plurality of driving openings distributed in the circumferential direction and each with a central eccentric receiving opening. The eccentric shaft 14 engages in the respective central eccentric receiving opening and is connected in a rotationally fixed manner to the rotor 4 of the electric machine 2.The eccentric shaft 14 is designed as a hollow shaft and is rotatably mounted on the pedal crankshaft 6. The electric machine 2 is designed as a generator.

[0027] The two eccentric wheels 12.1, 12.2 are arranged on the eccentric shaft 14 on eccentrics rotated by 180° to one another with respect to the rotation axis 7. A first bearing is arranged radially between a first eccentric of the eccentric shaft 14 and the first eccentric wheel 12.1, with a second bearing being arranged radially between a second eccentric of the eccentric shaft 14 and the second eccentric wheel 12.2. The respective eccentric wheel 12.1, 12.2 runs in the ring gear toothing 13. The ring gear toothing 13 is arranged in a rotationally fixed manner in the housing 8. In each case, a carrier bolt 10 is passed through a respective driving opening on the first eccentric wheel 12.1 and a respective driving opening on the second eccentric wheel 12.2. The respective first planetary roller 11.1 comes into contact, at least temporarily during operation of the eccentric gear 5, in the respective drive opening on the first eccentric gear 12.1. The respective second planetary roller 11.2 comes into contact, at least temporarily, with the respective drive opening on the second eccentric wheel 12.2 during operation of the eccentric gear 5. This can cause oscillations and vibrations during operation of the eccentric gear.

[0028] To reduce oscillations and vibrations during operation of the eccentric gear 15, a damper unit 15 is arranged in the torque flow between the pedal crankshaft 6 and the electric motor 2. In this case, the damper unit 15 is arranged in the torque flow between the pedal crankshaft 6 and the planetary carrier 9. The damper unit 15 comprises a spring channel 16, which is formed integrally with the first pedal hub 41, and a plurality of springs 17 arranged in the spring channel 16, which can be actuated, in particular compressed, via actuating elements 18 on the planetary carrier 9. Thus, the spring channel 16, the pedal crankshaft 6, both pedal hubs 41, 42, and the pedals connected thereto via cranks (not shown in detail) are configured to transmit drive power from a user into the eccentric gear 5.The spring channel 16 thus serves as the input shaft of the damper unit 15, with the springs 17 being provided for vibration damping, and the planetary carrier 9 being provided as the output shaft for the damper unit 15. To transfer the drive power from the damper unit 15, an actuating element 18 is arranged on the planetary carrier 9 for each spring 17 of the damper unit 15.

[0029] As can be seen from Figure 3, the planet carrier 9 has a total of four actuating elements 18 evenly distributed over the circumference as well as eight bores 43 for receiving the carrier bolts 10. The actuating elements 18 extend in the axial direction towards the spring channel 16. Furthermore, the planet carrier 9 has a central bore 44 for receiving a bearing 20.1 and rotatably supporting the planet carrier 9 on the pedal crankshaft 6, in particular indirectly via the pedal hub 41, as can be seen from Figure 1. The spring channel 16 is connected to the pedal crankshaft 6 in a rotationally fixed manner indirectly via the pedal hub 41.

[0030] Figure 2 shows the spring channel 16 with the four springs 17 of the damper unit 15. All four springs 17 are identical, evenly distributed in the circumferential direction in the spring channel 16 and spaced from one another by stop elements 19 in the spring channel 16. Free spaces for receiving the actuating elements 18 are arranged on the spring channel 16 radially outside the stop elements 19. All stop elements 19 are arranged on a first circular path which has a smaller diameter than a second circular path on which all actuating elements 18 are arranged. The stop elements 19 are connected in one piece to the respective spring channel 16 and extend from the spring channel 16 in the axial direction to the planet carrier 9, with two springs 17 coming to rest on each stop element 19 in the circumferential direction.The stop elements 19 preload the springs 17 in the spring channel, whereby the actuating elements compress the springs 17 upon relative rotation between the spring channel 16 and the planet carrier 9, thereby dampening vibrations. In this case, the springs are designed as arc springs. The damper unit 15 is provided for single-stage damping in a torque range of 20 Nm to 160 Nm and has a torsion angle of approximately 8° to 20°. Alternatively, and not shown here, the damper unit 15 can be designed for multi-stage damping, in which case different spring lengths and / or different spring types are preferably provided for the damper unit 15.

[0031] Figure 5 shows a human-powered vehicle 30 with a device 1 according to the invention, which is part of a drive arrangement of the human-powered vehicle 30. The human-powered vehicle 30 is designed as an e-bike, which is essentially formed from a frame 21 and a front wheel 22 and a rear wheel 23. The drive arrangement serves to drive the rear wheel 23. The rear wheel 23 thus forms a drive wheel of the e-bike, wherein the front wheel 22 is not driven in this case. The drive arrangement comprises a generator module 24, a drive module 25, and an energy storage module 26. The generator module 26 is arranged in the region of the bottom bracket and can be driven by a user via pedal force in order to generate electrical energy for the drive module 25. For this purpose, the generator module 24 has two pedal cranks 27 arranged diametrically opposite one another, which are set in rotation by pedal force in order to generate electrical power in the generator module 24.In this case, only one of the two pedal cranks 27 is shown. The bicycle has no mechanical drive connection between the pedal cranks 27 and the drive wheel 23. The generator module 24 is electrically connected to the drive module 25 and the energy storage module 26 only via an electrical line 28 in order to provide the electrical energy required for the drive module 25. The drive module 25 can, for example, be designed as a wheel hub motor integrated into the rear wheel 23, which transmits an electrical drive torque to the rear wheel 23. The drive module 25 can be supplied directly by the electrical energy generated by the generator module 24 or indirectly by the electrical energy stored in the energy storage module 26. The generator module 24 has the electrical machine 2 designed as a generator and the eccentric gear 5, which are jointly accommodated in a housing 8 arranged on the frame 21.For a detailed description of the functionality, reference is made to the state-of-the-art document mentioned above.

[0032] List of reference symbols

[0033] 1 device

[0034] 2 electric machine

[0035] 3 Stator

[0036] 4 Rotor

[0037] 5 eccentric gears

[0038] 6 Crankshaft

[0039] 7 Rotation axis

[0040] 8 housings

[0041] 8.1 Housing cover

[0042] 9 planet carriers

[0043] 10 support bolts

[0044] 11.1 first planetary roller

[0045] 11.2 second planetary roller

[0046] 12.1 first eccentric wheel

[0047] 12.2 second eccentric wheel

[0048] 13 Ring gear teeth

[0049] 14 Eccentric shaft

[0050] 15 Damper unit

[0051] 16 spring channel

[0052] 17 spring

[0053] 18 Actuating element on the planet carrier

[0054] 19 stop elements in the spring channel

[0055] 20.1 Warehouse

[0056] 20.2 Warehouse

[0057] 20.3 Camp

[0058] 20.4 Warehouse

[0059] 21 frames

[0060] 22 front wheel

[0061] 23 rear wheel

[0062] 24 generator module

[0063] 25 drive module

[0064] 26 Energy storage module 27 Crank

[0065] 28 Line

[0066] 30 muscle-powered vehicle

[0067] 40 Power electronics 41 Pedal hub

[0068] 42 pedal hub

[0069] 43 Hole

Claims

Patent claims 1. Device (1) for a muscle-powered vehicle (30), comprising an electric machine (2) with a stator (3) and a rotor (4), an eccentric gear (5) arranged coaxially to the electric machine (2), a pedal crankshaft (6) arranged on a common axis of rotation (7) with the electric machine (2) and the eccentric gear (5), and a housing (8) for accommodating the electric machine (2), the eccentric gear (5) and essentially also the pedal crankshaft (6), wherein the eccentric gear (5) has a planetary carrier (9) with a plurality of carrier bolts (10) and at least one planetary roller (11.1, 11.2) rotatably arranged on the respective carrier bolt (10), at least one eccentric wheel (12.1, 12.2).2) with a plurality of driving openings and a central eccentric receiving opening, a ring gear toothing (13) and an eccentric shaft (14), characterized in that a damper unit (15) is arranged in the torque flow between the pedal crankshaft (6) and the electric machine (2), comprising a spring channel (16) and a plurality of springs (17) arranged in the spring channel (16).

2. Device (1) according to claim 1, characterized in that the damper unit (15) is arranged in the torque flow between the pedal crankshaft (6) and the planet carrier (9).

3. Device (1) according to claim 2, characterized in that for each spring (17) of the damper unit (15) at least one actuating element (18) is arranged on the planet carrier (9).

4. Device (1) according to one of the preceding claims, characterized in that the damper unit (15) has two to six springs (17) which come into contact with stop elements (19) in the spring channel (16), wherein at least one spring (17) is designed as a compression spring.

5. Device (1) according to one of the preceding claims, characterized in that the spring channel (16) is at least indirectly connected to the pedal crankshaft (6).

6. Device (1) according to one of the preceding claims, characterized in that the planet carrier (9) is mounted at least on one side via a single bearing (20.1) or on both sides via two bearings (20.1, 20.2).

7. Device (1) according to one of the preceding claims, characterized in that the damper unit (15) has a rotation angle of at least 5° to a maximum of 35°.

8. Device (1) according to one of the preceding claims, characterized in that the damper unit (15) is designed to dampen at least in one stage or in several stages in a torque range of at least 20 Nm to a maximum of 180 Nm.

9. Device (1) according to claim 8, characterized in that the multi-stage damping damper unit (15) has different spring lengths and / or different spring types.

10. Muscle-powered vehicle (30) with a device (1) according to one of the preceding claims.

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