Vehicle that can be driven at least partially by muscle power

Abstract

The invention relates to a vehicle (1) which can be driven at least partially by muscle power, comprising at least two wheels and a drive unit having an electric machine with a rotor (2) and at least one stator segment (3), wherein the rotor (2) is designed to be connected in a rotationally fixed manner to a rim (4) of a drive wheel (5) of the vehicle (1), wherein the at least one stator segment (3) extends by a maximum of 180° and is designed to be connected in a rotationally fixed manner to at least one frame component of the vehicle (1).

Description

[0001] The invention relates to a vehicle that can be propelled at least partially by muscle power. In particular, the vehicle is designed as a bicycle or e-bike and has at least two wheels.

[0002] For example, WO 2020 / 002774 A1 discloses an electric vehicle comprising an electric motor mounted on at least one wheel, the electric motor comprising a rotor mounted on the outer side and a stator mounted on the inner side. The stator of the electric motor is arranged to act as an axle for the wheel, so that the stator is adapted to carry the loads between the wheel and the rest of the vehicle structure.

[0003] DE 10 2015 112 070 A1 describes an electric machine with a stator and at least one permanent magnet-free, non-energized rotor formed by an electrically conductive, short-circuit-capable bicycle rim. Two coils of the stator are positioned opposite the rotor and interact with it.

[0004] US 2019 / 0 118 902 A1 describes an electric auxiliary drive assembly for a vehicle with a frame and a spoked wheel. A rotatable drive ring with multiple magnets is mounted on a wheel. A stator carries a plurality of electromagnets and is mounted close to the wheel to overlap the electromagnets and magnets. Electrical energy is supplied to the stator to rotate the drive ring and thus the wheel.

[0005] DE 10 2010 022 939 A1 describes an electric bicycle with a frame and two wheels attached to it. At least one of the wheels is driven by a traction mechanism via pedal cranks. A battery provides electrical energy for an electric drive comprising a current-carrying coil and a magnet. These are arranged relative to one another on the frame and the wheel in such a way that the forces generated between them cause movement of one of the wheels.

[0006] DE 20 2020 003 320 U1 describes an electric drive system for a bicycle with a stator attached to the bicycle and a rotor provided with a permanent magnet on a wheel of the bicycle.

[0007] DE 10 2015 010 060 A1 describes a human-powered bicycle that also features a direct electric drive powered by a rechargeable battery. A rotor is integrated into the rear wheel as a pole wheel. Stator units are located on both sides of the bicycle frame as sub-elements.

[0008] JP 2006 - 001 516 A describes an electric bicycle. Power is generated by the interaction of an air coil on a wheel rim and a permanent magnet on an axle support frame.

[0009] DE 10 2019 130 767 A1 describes a drive and braking device for a vehicle. A rotor unit with a brake disc and a magnet section is coupled to a wheel of the vehicle, and a stator unit with a brake caliper is located on the vehicle frame.

[0010] DE 10 2021 131 055 B3 describes a drive-brake arrangement for a wheel of a human-powered vehicle. The stator of the disc motor is mounted on the frame. The disc-shaped rotor with permanent magnets is non-rotatably connected to a drive shaft. A brake caliper is provided on the frame, enclosing a brake disc, which is also non-rotatably connected to the drive shaft. The object of the invention is to create a vehicle that can be driven at least partially by muscle power and has an alternative drive unit. In particular, the drive unit should enable conventional wheel bearings and be designed to deliver high torque. This object is achieved by the subject matter of patent claim 1. Preferred embodiments can be found in the dependent claims, the description, and the figures.

[0011] A vehicle according to the invention comprises a drive unit for a vehicle that can be driven at least partially by muscle power, said drive unit comprising an electric machine with a rotor and at least one stator segment, wherein the rotor is designed to be connected in a rotationally fixed manner to a rim of a drive wheel of the vehicle, wherein the at least one stator segment extends by a maximum of 180° and is designed to be connected in a rotationally fixed manner to at least one frame component of the vehicle.

[0012] For example, the frame component is a section of a stationary frame or a sprung rocker that is only partially pivotable but not rotating on the frame. The stator segment can be attached to one or more frame sections, which can increase the stability of the attachment. The rotor is in particular arranged circumferentially on the drive wheel and is connected to the rim of the drive wheel in a rotationally fixed manner, forming a circular ring that is essentially the size of the drive wheel. For example, the rotor has a diameter of 20 to 30 inches. This makes it possible to create an electrical machine with particularly high torque. In contrast, the at least one stator segment only covers part of the circumference, namely a maximum of half the circumference, which reduces material and weight and improves heat dissipation.

[0013] According to one embodiment, the at least one stator segment extends a maximum of 90° along the drive wheel. For example, the at least one stator segment extends a maximum of 90° along the drive wheel and is attached to two frame sections of the vehicle. In particular, the at least one stator segment extends a maximum of 45° along the drive wheel. The vehicle is preferably designed as a bicycle, with the frame component being designed as a seat stay, chain stay, or swing arm.

[0014] According to one embodiment, the at least one stator segment has at least three coils. In particular, the at least one stator segment has a plurality of coils, wherein the number of coils is a multiple of three.

[0015] According to one embodiment, the electric machine has exactly one stator segment. Alternatively, the electric machine has exactly two stator segments, with the drive wheel and the rotor arranged thereon or integrated therein being arranged axially between the two stator segments.

[0016] According to one embodiment, the electric machine is designed as a radial flux machine. In other words, the magnetic flux flows in the radial direction through the air gap between the stator segment and the rotor. According to an alternative embodiment, the electric machine is designed as an axial flux machine. In an axial flux machine, the magnetic flux flows in the axial direction through the air gap between the stator segment and the rotor.

[0017] According to one embodiment, the electric machine has two motor halves. One motor half comprises, for example, a first rotor half and a first stator segment, while the other motor half comprises, for example, a second rotor half and a second stator segment. The rotor halves can be arranged on an inner circumference of the rim or on the front side of the rim. For example, spokes of the drive wheel are arranged between the two motor halves of the electric machine. Alternatively, the electric machine is arranged on one side of the drive wheel such that the spokes are attached to the rim either on one side or on the other side of the electric machine. Furthermore, alternatively, the electric machine can be arranged centrally on the drive wheel.

[0018] By reducing or enlarging the stator segment, particularly by changing the number of coils, the electric motor can be easily scaled for applications of varying power. The more coils the stator segment has, the greater its extension along the drive wheel. Due to the large rotor diameter, any gears, which are typically required to increase torque in wheel hub motors, can be dispensed with. This also saves costs, installation space, and friction losses.

[0019] According to the invention, the vehicle further comprises at least two wheels. In particular, the vehicle is designed as a bicycle or e-bike. For example, the vehicle can have three or more wheels, with either one or more wheels being electrically driven.

[0020] According to the invention, the vehicle further comprises a generator with a rotor and a stator, wherein the rotor of the generator is connected in a rotationally fixed manner to a pedal crankshaft of the vehicle. The generator is therefore designed as a pedal generator and converts the kinetic energy introduced by the rider via the pedals into electrical energy. The harder the rider pedals and the greater the resistance of the generator is set, the greater the electrical power generated by the generator. The electrical machine designed as an electric motor generates drive power at the wheel in accordance with an electrical power output of the generator. For example, the generator and the electric motor are connected to one another at least directly or indirectly. In particular, the vehicle can have several electric motors, each of which drives a wheel.In particular, no mechanical connection is provided between the pedal crankshaft and the drive wheel on which the electric motor is arranged. According to one embodiment, the vehicle comprises an electrical energy storage device that is electrically connected to the generator and the electric motor. The energy storage device serves, on the one hand, to store electrical energy, in particular to absorb the electrical energy of the generator, and, on the other hand, to provide electrical energy, in particular to feed electrical energy into the electric motor and drive the drive wheel.

[0021] According to the invention, the generator and the at least one stator segment are arranged in a common housing. Thus, the generator, designed as a pedal generator, and the at least one stator segment form a single unit that is mounted on the frame of the vehicle, in particular the bicycle. This simplifies assembly. In particular, this unit can be used for drive wheels of different sizes, for example, drive wheels with a diameter range of 27 to 30 inches, with only the interacting rotor being adapted to the size of the drive wheel.

[0022] Further measures improving the invention are described in more detail below together with the description of preferred embodiments of the invention with reference to the figures. Fig. 1 a highly simplified schematic representation of a vehicle according to the invention with a drive unit according to the invention, Fig. 2 a highly simplified schematic representation of the drive unit according to the invention according to a first embodiment, Fig. 3 a highly simplified schematic representation of the drive unit according to the invention according to a second embodiment, Fig. 4 a highly simplified schematic representation of the drive unit according to the invention according to a third embodiment and Fig. 5 a highly simplified schematic representation of a drive unit according to the invention, only partially shown, according to a fourth embodiment.

[0023] In Fig. Figure 1 shows a vehicle 1 according to the invention that can be driven at least partially by muscle power, comprising a rear wheel 5 configured as a drive wheel, a front wheel 11 pivotably mounted on a frame 9 via a fork 14, and a drive unit according to the invention. The vehicle 1 is configured as a bicycle, in particular as an e-bike.

[0024] A pedal crankshaft 7 is connected to pedals 10 via pedal cranks 15, wherein a generator 6 designed as a pedal generator is operatively connected to the pedal crankshaft 7. An electric machine with a rotor 2 and a stator segment 3 is drivingly connected to the drive wheel 5 of the bicycle in order to generate drive power at the drive wheel 5 in accordance with an electrical power of the generator 6. An electrical energy storage device 16 is arranged on the frame 9 and is electrically connected to the generator 6 and the electric machine on the drive wheel 5. In the present case, the rotor 2 of the electric machine is integrated in the drive wheel 5, in particular is connected in a rotationally fixed manner to the rim of the drive wheel 5. The stator segment 3 extends in the present case by 90° along the drive wheel 5 and is connected in a rotationally fixed manner to the frame 9.

[0025] When the rider pedals, the generator 6 generates electrical power that serves as a measure of the electrical energy from the energy storage device 16 fed into the electric machine on the drive wheel 5. In particular, the electrical drive power provided by the electric machine on the drive wheel 5 is the product of the electrical power of the generator 6 and a factor that can be selected by the rider by selecting the driving mode. There is no mechanical connection, in particular no chain or belt drive, between the wheel hub, which rotatably supports the drive wheel 5 on the frame 9, and the pedal crankshaft 7, so that the drive wheel 5 can only be driven by the electric machine.

[0026] By reducing or enlarging the stator segment 3, the electric motor can be easily scaled for applications of varying power. The more coils the stator segment 3 has, the greater its extension along the drive wheel 5. Due to the large diameter of the rotor 2, which is arranged circumferentially around the drive wheel 5, any gears that are usually required to increase torque in wheel hub motors can be dispensed with. This saves costs, installation space, and friction losses.

[0027] Fig. Figure 2 shows a highly simplified section of a drive wheel 5, which is connected to a wheel hub (not shown in detail) via spokes 13 and rotates about a rotational axis 16. The drive wheel 5 has a rim 4 and a tire 12 arranged thereon. A rotor 2 is arranged circumferentially on an inner circumference of the rim 4. Furthermore, a stator segment 3, which extends a maximum of 180° along the drive wheel 5, is arranged on the frame 9 of the bicycle. The rotor 2 and the stator segment 3 form the electrical machine configured as an electric motor, which in this case is designed as a radial flux machine.

[0028] Fig. Figure 3 shows, in a highly simplified form, another section of a drive wheel 5, which is connected to a wheel hub (not shown in detail) via spokes 13 and rotates about a rotational axis 16. The drive wheel 5 has a rim 4 and a tire 12 arranged thereon. Two rotor halves, which form a rotor 2, are arranged circumferentially on an inner circumference of the rim 4. Furthermore, two stator segments 3, which extend a maximum of 180° along the drive wheel 5, are arranged on the frame 9 of the bicycle. The rotor 2 and the stator segments 3 form the electric machine, which in this case is designed as a radial flux machine from two motor halves.

[0029] Fig. 4 shows, in a highly simplified form, another section of a drive wheel 5, which is connected to a wheel hub (not shown in detail) via spokes 13 and rotates about a rotational axis 16. The drive wheel 5 has a rim 4 and a tire 12 arranged thereon. A rotor half is arranged circumferentially on each end face of the rim 4, with the two rotor halves forming a rotor 2. Furthermore, two stator segments 3, which extend a maximum of 180° along the drive wheel 5, are arranged on the frame 9 of the bicycle. The rotor 2 and the stator segments 3 form the electric machine, which in this case is designed as an axial flux machine consisting of two motor halves. According to an alternative embodiment, one of the two rotor halves and the associated stator segment 3 can be omitted, whereby the electric machine no longer has two motor halves, making it more compact and less powerful.

[0030] Fig.Figure 5 shows, in a highly simplified form, a housing 8 designed to be mounted on the frame 9 of the vehicle 1. Both the generator 6 with the pedal crankshaft 7 and precisely one stator segment 3 are arranged in the housing 8. In particular, this unit can be used for different bicycles, with the stator segment 3 being compatible with different wheel diameters with a rotor integrated therein. List of reference symbols 1 vehicle 2 rotors 3 Stator segment 4 rim 5 drive wheel 6 Generator 7 Crankshaft 8 housings 9 frames 10 Pedal 11 Front wheel 12 tires 13 spokes 14 forks 15 crank 16 Rotation axis

Claims

[1] Vehicle (1) which is at least partially drivable by muscle power, comprising at least two wheels and a drive unit, having an electric machine with a rotor (2) and at least one stator segment (3), wherein the rotor (2) is designed to be connected in a rotationally fixed manner to a rim (4) of a drive wheel (5) of the vehicle (1), wherein the at least one stator segment (3) extends by a maximum of 180° and is designed to be connected in a rotationally fixed manner to at least one frame component of the vehicle (1), characterized by a generator (6) with a further rotor and a further stator, wherein the rotor of the generator (6) is connected in a rotationally fixed manner to a pedal crankshaft (7) of the vehicle (1) and the generator (6) and the at least one stator segment (3) are arranged in a common housing (8). [2] Vehicle (1) according to claim 1, characterized bythat at least one stator segment (3) extends by a maximum of 90°. [3] Vehicle (1) according to one of the preceding claims, characterized by that the at least one stator segment (3) has at least three coils. [4] Vehicle (1) according to one of the preceding claims, characterized by that the electrical machine has exactly one stator segment (3). [5] Vehicle (1) according to one of the preceding claims, characterized by that the electrical machine is designed as a radial flux machine. [6] Vehicle (1) according to one of claims 1 to 4, characterized by that the electrical machine is designed as an axial flux machine. [7] Vehicle (1) according to one of the preceding claims, characterized by that the electric machine has two motor halves.

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