HK1174594B - Drive arrangement, for example for an electric bicycle - Google Patents

Abstract

The present invention relates to a drive arrangement, comprising an electric motor, an energy source for electrical energy, and an energy transmission cable, which electrically connects the energy source to the electric motor and which is designed as a coaxial cable.

Description

Drive unit, for example for an electric bicycle

The invention relates to a drive device according to the generic concept of claim 1, with an electric motor, a power source and an energy transmission cable electrically connecting the energy source and the electric motor. The invention further relates to an electric light vehicle (LEV), in particular an electric bicycle, in particular a petelec (electric pedal-assisted vehicle) or E-Bike, with a drive according to the generic concept of claim 8. The invention also relates to a motor vehicle, in particular a single-track or two-track motor vehicle, in particular an electric scooter, battery car, scooter, motorcycle or automobile, according to the generic concept of claim 9.

For example, an electric bicycle, in particular a so-called petelec (electrically assisted bicycle, with electrically assisted pedal) is disclosed in the document "E-motion-einspezialvon radfahren & extra energy, org", published in 2009 by bvabilefeld publishers, and is becoming increasingly popular. The Pedelec is constructed basically as a conventional bicycle driven by foot pedals with a motor mounted thereto and supplied from a power source, the motor generating a driving force other than manual force when a force acts on the Pedelec's pedals. When the rider steps on the pedal, the motor starts to operate. The petelec user feels like riding downwind while riding.

Another type of electric bicycle is the so-called "E-Bike". When the accelerator lever is rotated, the motor starts to operate. The pedal can be not pedaled during riding, and the electric motor is only used for driving. The human and motor systems function independently of each other. The E-Bike may use only electric power or a mixture of electric power and manpower.

All such vehicles are provided with a drive unit, including an electric motor and a power source, regardless of the function and operation of the motor. The drive unit has an energy transmission cable electrically connected to the motor and the power source for transmitting electrical energy from the power source to the motor. An electronic device for converting the voltage of the power supply into the working voltage of the motor can be additionally arranged. Traditionally, the energy transmission cable is designed as a two-core cable with corresponding red and black markings to indicate the positive and negative polarity of the voltage.

The object of the present invention is to improve a drive of the type mentioned above with respect to installation space, processability and mechanical stability.

According to the invention, this object is achieved by a drive unit of the above-mentioned type with the features of claim 1, an electric light vehicle (LEV) of the above-mentioned type with the features of claim 8 and a motor vehicle of the above-mentioned type with the features of claim 9. Advantageous embodiments of the invention are described in the further claims.

According to the invention, the energy transmission cable of the drive device of the above-mentioned type is a coaxial cable.

Its advantage is that the drive unit is compact because of the energy transmission cable, and the occupied structural space is small, and the energy transmission cable has high mechanical stability simultaneously. The coaxial cable is simple to process and can be connected with a socket. While the energy transmission cable is shielded from unwanted high frequency radiation coupling. The energy transmission cable can also be used as a data transmission line from the electric motor to a control electronics without the need to provide an additional line for this purpose.

The coaxial cable has at least an inner conductor, an outer conductor, an insulator arranged between the inner and outer conductors and an electrically insulating sheath surrounding the outer conductor, so that the drive unit is particularly compact and mechanically stable on such energy transmission cables.

The outer conductor and the inner conductor are each electrically connected to a power source and the motor, so that the outer conductor can also transmit electrical energy, rather than just a shield.

Conveniently, the motor is a dc motor or an ac motor.

To provide a high drive force for the drive, the coaxial cable is designed to be able to transmit high currents, in particular currents of greater than or equal to 30A, in particular currents of greater than or equal to 50A.

To achieve high torques of the drive, the coaxial cable is designed to withstand voltages of from 0 to 100V, in particular 48V.

To achieve a high energy density of the energy source, the energy source is designed as a battery, in particular a nickel metal cyanide battery, a nickel cadmium battery, a lead battery or a lithium ion battery and/or a generator.

According to the invention, an electric bicycle in an electric light vehicle (LEV) of the above-mentioned type is provided with a drive unit as just described.

Its advantage is, the drive arrangement of LEV is compact because of the energy transmission cable, and the shared structure space is little, and the energy transmission cable has high mechanical stability simultaneously. The coaxial cable is simple to process and can be connected with a socket. While the energy transmission cable shields against unintentional high-frequency radiation coupling. The energy transmission cable can also be used as a data transmission line from the electric motor to a control electronics without a line being necessary for this purpose.

According to the invention, a motor vehicle of the above-described type is provided with a drive unit of the type just described.

Its advantages are compact drive unit of motor vehicle, small space occupied by energy transmission cable, and high mechanical stability of energy transmission cable. The coaxial cable is simple to process and can be connected with a socket. While the energy transmission cable shields against unintentional high-frequency radiation coupling. The energy transmission cable can also be used as a data transmission line from the electric motor to a control electronics without a line being necessary for this purpose.

The invention is further elucidated below with the aid of a schematic drawing.

Fig. 1 shows a preferred embodiment of a drive device according to the invention;

fig. 2 is a cross-sectional view of the region a taken along the line I-I in fig. 1.

Fig. 1 shows a preferred embodiment of the drive device according to the invention, comprising an electric motor 10, a power source 12 and an energy transmission cable 14 electrically connecting the electric motor 10 and the power source 12.

According to the invention, the energy transmission cable 14 is designed as a coaxial cable. As seen in fig. 2, the coaxial cable includes an inner conductor 16 and an outer conductor 18 coaxially surrounding the inner conductor 16 with a dielectric 20 between the inner conductor 16 and the outer conductor 18. The coaxial cable 12 also has a jacket 22 made of an electrically insulating material surrounding the outer conductor.

The motor 10 is, for example, a DC motor, and the coaxial cable 12 transmits DC power having a current intensity of 30A or 50A from the power source 12 to the motor 10.

The power source 12 is preferably a lithium battery. However, the power source 12 may be a generator that converts mechanical driving energy into electric energy instead of an accumulator such as a battery or an accumulator. The generator may be driven by an internal combustion engine, for example.

An electric vehicle, for example a Pedelec or E-bike, is particularly advantageous in that the coaxial cable 12, which transmits the electrical energy from the power source 12 to the electric motor 10, has the same or partly better mechanical properties in terms of density, bending stiffness, insensitivity to environmental influences, durability and tensile strength as the bowden wire used on the bicycle. The coaxial cable 12 can thus be used without special measures like a bowden cable on a petelec. At the same time, the coaxial cable 12 is constructed in such a way that the cable for transmitting a high current from the power supply 12 to the electric motor 10 is compact, i.e. requires little installation space. At current strengths of 30A, 50A or higher, it requires a much smaller installation space than other conventional two-core cables.

In addition, a large number of devices and machines are available for machining, mass production, refurbishing coaxial cables and installing plugs at their ends, and even for automation and mass production.

Furthermore, such drives usually require cables for the transmission of data in the form of high-frequency signals, for example from a motor control unit to the motor 10 or from the power supply 12 to the motor control unit. A particular advantage is that this function can be performed using the coaxial cable, since it already has the necessary shielding and impedance for the transmission of electronic high-frequency signals. Therefore, different types of cables are not needed for data transmission and energy transmission, and the data transmission and the energy transmission can be realized by equipping the same coaxial cable with different plugs. This simplifies the production and installation procedure and the logistics associated therewith.

Claims (6)

1. An electric bicycle having a drive unit which comprises a direct current motor (10), a power source (12) in the form of a battery and/or generator, a motor control unit, an energy transmission cable (14) which electrically connects the power source (12) to the direct current motor (10), characterized in that the energy transmission cable (14) is designed in the form of a first coaxial cable, the energy transmission cable (14) having at least one inner conductor (16), one outer conductor (18), an insulator (20) arranged between the inner conductor (16) and the outer conductor (18) and an electrically insulating sheath (22) which surrounds the outer conductor; an outer conductor and an inner conductor are respectively electrically connected with the power box direct current motor; wherein a second coaxial cable is included for transmitting data in the form of a high frequency signal from the motor control unit to the direct current motor (10), said second coaxial cable having the same form as the first coaxial cable.

2. The electric bicycle according to claim 1, wherein the first coaxial cable (14) is designed to transmit a current of 30A or more.

3. The electric bicycle according to claim 2, characterized in that the first coaxial cable (14) is designed to be able to transmit a current of 50A.

4. An electric bicycle according to any of the preceding claims 1-3, characterized in that the first coaxial cable (14) is designed to withstand a voltage of from 0 to 100V.

5. The electric bicycle according to claim 4, characterized in that the first coaxial cable (14) is designed to withstand a voltage of 48V.

6. The electric bicycle according to claim 1, wherein the power source (12) is a nickel metal cyanide battery, a nickel cadmium battery, a lead battery or a lithium ion battery.