Patent Application
20110198144
1. Technical Field of the Present Disclosure
The present disclosure relates to an electric bicycle, and in particular relates to an electric bicycle operated by a slim motor.
2. Description of the Related Art
For a conventional electric bicycle modified from a traditional bike, a motor is mounted in a wheel hub, usually the rear wheel hub, to rotate the wheel. However, before the motor is mounted to the hub, spokes of the traditional bicycle must be first demounted. Thus, when the motor is remounted, the spokes are re-fixed to the hub one by one, which requires a lot of time for assembly. Also, since wheels have different specifications for different bicycle brands, it is necessary to adjust the motor design for each different bicycle brand, which increases manufacturing costs.
There is another structure for the conventional electric bicycle, wherein the motor is fixed to a frame of the bike, and the wheel is rotated by a chain, a belt or gears coupled to the motor. However, the motor mounted to the frame may cause the bicycle to be imbalanced and occupy considerable space. Also, the durability of the frame may be weakened due to the installation of the motor. In addition, riding the bicycle may be more difficult due to the considerable weight and size of the motor.
Taiwan (R.O.C.) patent No. 1296596 discloses a driving mechanism for an electric bicycle comprising a motor and a modified structure of a pedal shaft which is connected to a wheel by a chain. Note that the frame is not modified. Meanwhile, Taiwan (R.O.C.) patent No. M356689 discloses a transmission wheel disposed on a front wheel or a rear wheel of a bike. Motors are disposed on a frame of the bicycle to drive the transmission wheel to rotate the front and rear wheels.
For the design of motors installed in the hub of a bike, Taiwan (R.O.C.) patent No. 352804 discloses an improved structure of a motor having improved silicon steel, coils, and magnets, forming a slim supersonic motor, which can be disposed on a front or rear wheel to serve as an engine. Meanwhile, Taiwan (R.O.C.) patent No. 313554 discloses an extra-slim electric motor in which heavy silicon steel and coil are replaced by a minor film and film coil. The extra-slim electric motor can be disposed on a front or rear wheel to serve as an engine.
Additionally, U.S. Pat. No. 5,368,122 discloses a DC motor with bevel pinions, a driving mechanism and a transmission collar which is installed on a rear triangular support mechanism. The transmission collar is rotated by the DC motor and the bevel pinions. The mechanism produces little noise and a smooth ride. Also, in U.S. Pat. No. 6,412,800, a kit including an electric motor, a control, and gears is mounted below a pedal axle of a bicycle to power a bicycle and U.S. Pat. No. 6,131,683 discloses an electric bicycle comprising a DC flat type motor utilizing an axial magnetic flux, which rotates a wheel by means of a control circuit, a pedal load sensor, pedal rotation speed sensor, a torque sensor, a speed reduction mechanism, transmission device and gears. In U.S. Pat. No. 585,753, an electric motor, a controller and a transmission mechanism are disposed in a rear wheel hub of a bicycle.
In the described patents, the electric motor must be mounted on the frame of a bicycle and be coupled to a wheel thereof via gears or a transmission mechanism, which results in a high cost and increased weight. Alternatively, the electric motor may be mounted in the hub of the bike. However, spokes of the bicycle must be re-fixed to the hub one-by one for remounting, which requires a lot of time for assembly.
Referring to
The present disclosure provides an electric bicycle comprising a slim motor connected to the hub via a coupling element, wherein the slim motor is mounted near the hub. No transmission mechanism is needed. In addition, since the slim motor is mounted on the brake disc, it is not necessary to modify the frame. The slim motor is lighter than typical electric motors, which makes riding of the electric bicycle convenient.
An embodiment of an electric bicycle of the present disclosure comprises a frame comprising at least one supporting member, at least one wheel comprising a shaft fixed to the supporting member and a hub rotatable about the shaft, and at least one slim motor comprising a rotor coupled to the hub and rotating about an axis aligned with the shaft, wherein the slim motor drives the hub to rotate about the shaft. The rotor is coupled to the hub by a coupling element. The coupling element is an adapter tightly fitted to the rotor.
The adapter comprises a connecting portion having a first screw hole corresponding to a second screw hole formed on the rear hub, and a fitting portion connected to the connecting portion and tightly fitted to the rotor of the slim motor. A bolt passes through the first and second screw holes to fix the adapter to the hub. The fitting portion is perpendicular to the connecting portion.
The slim motor further comprises a housing having a disc shape with a through hole through which the axis passes, and a stator disposed in the housing and corresponding to the rotor, wherein the rotor is disposed in the housing and around the through hole. The fitting portion extends into the through hole and is tightly fitted with the rotor. The through hole is formed at the center of the disc shape.
A detailed description is given in the following embodiments with reference to the accompanying drawings.
The present disclosure can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings which are given by way of illustration only, and thus are not limitation of the present disclosure and wherein:
a and 2b depict a slim motor for the electric bicycle of the present disclosure;
To solve the described problems, a slim motor is provided for the electric bicycle of the present disclosure. The slim motor is coupled to the wheel and has an axis aligned with a shaft of the wheel. For example, the axis is mounted to the brake disc which is fixed to the wheel hub. The torque generated by the motor rotates the wheel directly, without a transmission mechanism. In this way, the slim motor does not occupy additional space of the bicycle. Since the slim motor is not mounted in the hub, there is no need to demount the spokes of the wheel from the hub and remount them. When the bicycle has a quick release device and brake disc, the slim motor of the present disclosure can be quickly and conveniently mounted to the bicycle to reduce the cost and time for assembly.
a and 2b depict a slim motor 50 of the present disclosure. As the slim motor 50 has axial magnetic flux, the magnetic flux area of the slim motor 50 is larger than that of the conventional outer-rotor motor, whereas the size is smaller than that of the conventional outer-rotor motor. The thickness of the conventional outer-rotor motor is over 10 cm, whereas the thickness of the slim motor 50 is only about 3 cm. The slim motor 50 is suitable for an electric bicycle due to its torque, size and weight advantages. The torque generated by the slim motor 50 is large enough to drive a bicycle without any transmission mechanism. The slim motor 50 can be an outer-rotor type or inner-rotor type motor according to requirements. The detailed structure of the slim motor 50 is described as follows.
The slim motor 50 comprises a housing 52 having a disc shape with a through hole 54. In this embodiment, the through hole 54 is formed on the center of the housing 52. The wall of the through hole 54 is connected to a rotor 56 (see
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When a rider steps on a pedal to manually move a bicycle, the slim motor 50 generates torque to drive the bicycle simultaneously so as to help the rider to move the bicycle more easily. In addition, the electric bicycle 1000 can also be only operated by the slim motor 50, and in such a condition, it would be a pure electric bicycle.
While the present disclosure has been described by way of example and in terms of preferred embodiment, it is to be understood that the present disclosure is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.
This application claims the benefit of U.S. Provisional Application No. 61/303,777, filed on Feb. 12, 2010.
| Number | Date | Country | |
|---|---|---|---|
| 61303777 | Feb 2010 | US |
