Electric bicycle drive system having moisture-proof structure

Abstract

According to some embodiments of the present invention, a drive system installed in an electric bicycle to assist power of a pedal comprises: a housing installed on a crankshaft of the electric bicycle; a drive motor accommodated in the housing to generate a driving force; a gear unit comprising a plurality of gears connected to the crankshaft, the gear unit being in contact with the drive motor to receive the driving force; a PAS sensor unit for sensing pedaling information; and a control unit for controlling an output of the drive motor on the basis of the pedaling information received from the PAS sensor unit, wherein the housing has a moisture-proof structure including: an exhaust unit formed in the front-rear direction to discharge heat generated in the housing; and a moisture-permeable unit installed in the exhaust unit to block liquid movement and allow gas to pass therethrough.

Description

Electric bicycle drive system with moisture-proof structure

[0001] The present invention relates to an electric bicycle drive system having a moisture-proof structure, and more specifically, to an electric bicycle drive system having a moisture-proof structure that discharges heat generated from a motor and blocks the penetration of moisture.

[0002]

[0003] Electric bicycles are a faster and more convenient means of transportation compared to regular bicycles, and as an effective way to avoid urban traffic congestion, many people use them on a daily basis, leading to a rapid increase in the electric bicycle market recently.

[0004] In particular, due to its eco-friendly and highly energy-efficient characteristics, it is gaining popularity as a personal mode of transportation and is becoming widely popular among people of various age groups and riding experience.

[0005] The electric motor of an electric bicycle generates power by receiving electricity from the battery and provides driving force by rotating the pedals. To dissipate the heat generated during the motor's operation, the motor cover is formed with vents for air intake and exhaust.

[0006] However, due to the nature of conventional electric motors being installed on the underside of the bicycle, there is a high probability that water splashing from the ground or external moisture will enter the interior through the vents. This problem acts as a major cause of drive unit failure or shortened motor lifespan. In particular, this issue becomes more pronounced in rainy weather or environments with high humidity.

[0007] To solve this problem, there is a need to develop an electric bicycle motor with a moisture-proof structure that can effectively dissipate internal heat while blocking the ingress of external moisture.

[0008]

[0009] One objective of the present invention is to provide a motor for an electric bicycle that includes a moisture-proof function.

[0010] The objectives of the present invention are not limited thereto, and other unmentioned objectives will be clearly understood by a person skilled in the art from the description below.

[0011]

[0012] An electric bicycle drive system having a moisture-proof structure according to one embodiment of the present invention is installed on an electric bicycle to assist pedal power, and comprises a housing installed on the crank shaft of the electric bicycle, a drive motor housed inside the housing to generate driving force, a gear section composed of a plurality of gears connected to the crank shaft and receiving driving force in contact with the drive motor, a PAS sensor section for detecting pedaling information, and a control section for controlling the output of the drive motor based on pedaling information received from the PAS sensor section. The housing may include an exhaust section formed in the front and rear directions to discharge heat generated inside, and a moisture-permeable section installed in the exhaust section to block liquid movement and allow gas to pass through.

[0013] Additionally, the exhaust section may include an exhaust hole having a first diameter and a moisture-permeable groove that communicates with the exhaust hole and is drawn inward so that a moisture-permeable section can be installed.

[0014] In addition, the moisture permeable groove is formed with a second diameter different from the first diameter of the exhaust hole, and the second diameter can be formed with a size larger than the first diameter.

[0015] In addition, the moisture-permeable portion may be formed with an outer diameter larger than the first diameter and equal to or smaller than the second diameter.

[0016] Additionally, the moisture-permeable section may include a moisture-permeable filter formed with a membrane structure that allows gas to pass through while blocking liquid inflow, a cover member having a plurality of perforated holes formed to prevent the moisture-permeable filter from detaching and communicating with an exhaust hole, and a sealing member provided between the moisture-permeable filter and the cover member to block moisture penetration.

[0017]

[0018] According to an electric bicycle drive system having a moisture-proof structure according to one embodiment of the present invention, external air is introduced into the interior of the housing to cool the drive motor, while preventing moisture from entering, thereby increasing the lifespan of the motor.

[0019] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the attached drawings.

[0020]

[0021] FIG. 1 is a schematic diagram showing an electric bicycle drive system having a moisture-proof structure according to one embodiment of the present invention installed on an electric bicycle.

[0022] FIG. 2 is a block diagram of an electric bicycle drive system having a moisture-proof structure according to one embodiment of the present invention.

[0023] FIG. 3 is a perspective view schematically showing a part of an electric bicycle and an electric bicycle having a moisture-proof structure according to one embodiment of the present invention.

[0024] Fig. 4 is a front view of the external housing of Fig. 3.

[0025] Fig. 5 is an exploded view of the outer housing of Fig. 3.

[0026] Figure 6 is a block diagram showing the gear section of Figure 2.

[0027] Figure 7 is a block diagram showing the PAS sensor section of Figure 2.

[0028]

[0029] The embodiments described in this specification and the configurations illustrated in the drawings are merely preferred examples of the disclosed invention, and various modifications that may replace the embodiments and drawings of this specification may exist at the time of filing this application.

[0030] Identical reference numbers or symbols in each drawing of this specification represent parts or components that perform substantially the same function. The shapes and sizes of the elements in the drawings may be exaggerated to provide a clear description.

[0031] The terms used herein are for describing embodiments and are not intended to limit or / or restrict the disclosed invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to indicate the presence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0032] Terms including ordinal numbers, such as "first," "second," etc., as used in this specification may be used to describe various components, but said components are not limited by said terms, and said terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be named the second component, and similarly, the second component may be named the first component.

[0033] First, an electric bicycle (20) having an electric bicycle drive system (10) with a moisture-proof structure is described.

[0034] FIG. 1 is a schematic diagram showing an electric bicycle drive system having a moisture-proof structure according to one embodiment of the present invention installed on an electric bicycle.

[0035] Referring to FIG. 1, the electric bicycle (20) generally comprises a frame (21) equipped with a saddle (22), a fork (23) mounted on the front of the frame (21) and configured to be directionally oriented, a handle (24) installed on the upper side of the fork (23), a pair of wheels (25) mounted on the lower end of the fork (23) and the rear end of the frame (21), a crank (27) connected to the frame (21) by a crank shaft (26), a pedal (28) mounted on the crank (27), and an electric bicycle drive system (10) having a moisture-proof structure provided adjacent to the crank shaft (26) in the frame (21).

[0036] Hereinafter, an electric bicycle drive system (10) having a moisture-proof structure according to one embodiment of the present invention will be described in detail with reference to the above.

[0037] FIG. 2 is a block diagram of an electric bicycle drive system having a moisture-proof structure according to an embodiment of the present invention. FIG. 3 is a perspective view schematically showing a part of an electric bicycle and an electric bicycle having a moisture-proof structure according to an embodiment of the present invention. FIG. 4 is a front view of the outer housing of FIG. 3.

[0038] Referring to FIGS. 2 to 4, an electric bicycle drive system (10) having a moisture-proof structure according to one embodiment of the present invention can provide driving force to a crank (27) to rotate a wheel (25) mechanically connected to the crank (27). The electric bicycle drive system (10) having a moisture-proof structure may be a shaft drive type that transmits power from a drive motor to a wheel using a vertically connected shaft (320). As shown in FIG. 2, the electric bicycle drive system (10) having a moisture-proof structure includes a housing (100), a drive motor (200), a gear unit (300), a PAS sensor unit (400), a battery (500), and a control unit (600).

[0039] The housing (100) can be mounted adjacent to the crankshaft (26) of the frame (21). The housing (100) has an internal space formed to accommodate a drive motor (200), a gear section (300), and a control section (600) inside. The housing (100) protects the drive motor (200), the gear section (300), and the control section (600) from external foreign matter. Additionally, the housing (100) can be formed to cover a shaft (320) and a sprocket (not shown) coupled to the rear wheel, which will be described later. The housing (100) can be formed from a metal or synthetic resin material. The housing (100) includes an exhaust section (110) and a moisture permeable section (120).

[0040] The exhaust section (110) is formed at the front and rear of the housing (100) and discharges heat generated from the drive motor (200) housed inside the housing (100). The exhaust section (110) can draw air in at the front of the housing (100) and discharge air at the rear. The exhaust section (110) includes an exhaust hole (111) and a moisture permeability groove (112).

[0041] The exhaust hole (111) is used as a passage for introducing air from the outside of the housing (100) into the inside. The exhaust hole (111) may be formed as a plurality of holes at the front and rear of the housing (100), respectively. The exhaust hole (111) may be formed in a circular shape and may have a first diameter (D1).

[0042] The moisture-permeable groove (112) may be provided as a groove in which the moisture-permeable part (120) is mounted. The moisture-permeable groove (112) is formed to be drawn inward from the outer surface of the housing (100). The moisture-permeable groove (112) is formed at a position overlapping with the exhaust hole (111). The moisture-permeable groove (112) may be formed in a circular shape and may have a second diameter (D2). For example, the second diameter (D2) of the moisture-permeable groove (112) may be formed to be larger than the first diameter (D1) of the exhaust hole (111) to support one side of the moisture-permeable part (120).

[0043] The moisture-permeable section (120) is installed in the moisture-permeable groove (112). The moisture-permeable section (120) may be provided in a number corresponding to the moisture-permeable groove (112). The total height of the moisture-permeable section (120) may be formed to be equal to the depth of the moisture-permeable groove (112).

[0044] A moisture-permeable section (120) is installed in front of the exhaust hole (111) to block liquid from entering the exhaust hole (111) and to allow gas to pass through. Specifically, the moisture-permeable section (120) blocks water from entering the housing (100) and can discharge air or water vapor from the inside to the outside of the housing (100).

[0045] FIG. 5 is an exploded view of the outer housing of FIG. 3. Referring to FIG. 5, the moisture-permeable section (120) includes a moisture-permeable filter (121), a sealing member (122), and a cover member (123).

[0046] A moisture permeable filter (121) is inserted into a moisture permeable groove (112). The moisture permeable filter (121) may be provided in a disc shape and may be provided with a size equal to or smaller than the second diameter (D2) of the moisture permeable groove (112). The moisture permeable filter (121) is provided to be replaceable. The moisture permeable filter (121) may be formed as a membrane structure. For example, the moisture permeable filter (121) may be formed from a polytetrafluoroethylene (PTFE) material. That is, the moisture permeable filter (121) can allow gas to pass through and block the movement of liquid.

[0047] When the moisture permeable filter (121) is provided to be smaller than the second diameter (D2) of the moisture permeable groove (112), the moisture permeable filter (121) may have a different shape from the moisture permeable groove (112). That is, the distance between the moisture permeable filter (121) and the moisture permeable groove (112) is irregularly formed to generate air vortices, thereby allowing the amount of fluid flowing in from the outside to be controlled.

[0048] A sealing member (122) is inserted into a moisture-permeable groove (112). One side of the sealing member (122) contacts the moisture-permeable filter (121) and the other side contacts the cover member (123). It may be provided to be in close contact with the inner surface of the moisture-permeable groove (112). For example, the sealing member (122) may be formed of an elastic rubber or silicone material.

[0049] The sealing member (122) may be formed in a ring shape, with a through hole (1221) formed in the center that communicates with the exhaust hole (111) of the exhaust section (110). At this time, the outer diameter of the sealing member (122) may be formed to be equal to or smaller than the second diameter (D2) of the moisture permeability groove (112). Additionally, the diameter of the through hole (1221) may be formed to be equal to or larger than the first diameter (D1) of the exhaust hole (111).

[0050] As another example, the sealing member (122) may be placed on the moisture permeable filter (121). That is, the moisture permeable filter (121) may have a mounting groove (not shown) formed on the surface that contacts the sealing member (122), and the sealing member (122) may be placed in the mounting groove (not shown) of the moisture permeable filter (121) to adjust the contact area. At this time, the mounting groove (not shown) may have an uneven surface formed therein to more easily adjust the contact area with the sealing member (122).

[0051] The cover member (123) seals the opening of the moisture permeable groove (112) while the moisture permeable filter (121) and the sealing member (122) are installed in the moisture permeable groove (112). The cover member (123) can be detachably mounted to the moisture permeable groove (112). The cover member (123) may be formed in the shape of a disc, with an outer diameter corresponding to the first diameter (D1) of the moisture permeable groove (112). A through hole (1231) communicating with the exhaust hole (111) and the through hole (1221) may be formed in the cross section of the cover member (123). Multiple through holes (1231) may be provided.

[0052] The cover member (123) may be provided with a fixing member (1232) on its side. The fixing member (1232) may cause the outer surface of the cover member (123) to be in close contact with the inner surface of the moisture-permeable groove (112). For example, the fixing member (1232) may be formed of a rubber or silicone material. At this time, the cover member (123) may have a fixing groove (not shown) formed along its circumference so that the fixing member (1232) is seated on its side.

[0053] The drive motor (200) is provided inside the housing (100). The drive motor (200) receives electrical energy from the battery (500), converts it into mechanical energy, and transmits power to the gear section. The drive motor (200) may be provided as a DC motor that generates rotational force through magnetic repulsion, including a stator and a rotor. The drive motor (200) includes a stator (not shown) and a rotor (not shown).

[0054] The stator is electrically connected to the battery (500). The stator is in the form of a coil wound multiple times, and current supplied from the battery (500) passes through it to generate a magnetic field.

[0055] The rotor is rotatably provided at a predetermined interval from the stator. The rotor is equipped with a plurality of permanent magnets and rotates by receiving a magnetic field generated from the stator. One side of the rotor is connected to the gear unit (300) to transmit rotational mechanical energy to the gear unit (300).

[0056] At this time, the drive motor (200) may be an air-cooled motor that cools the heat generated by the rotation of the rotor with air introduced through the exhaust part (110) of the housing (100).

[0057] The gear unit (300) is provided inside the housing (100). The gear unit (300) is mechanically connected to the drive motor (200). The gear unit (300) receives power from the drive motor (200) and rotates the wheel (25). Hereinafter, the gear unit (300) is described as transmitting power from the drive motor (200) to the rear wheel in a shaft drive manner. FIG. 6 is a block diagram showing the gear unit of FIG. 2. Referring to FIG. 6, the gear unit (300) includes a front gear (310), a shaft (320), and a rear gear (330).

[0058] First, one side of the front gear (310) is connected to a crankshaft (26) to which the drive motor (200) and pedal (28) are connected, and the other side is connected to a shaft (320). At this time, the front gear (310), shaft (320), and rear gear (330) can be connected in the form of a bevel gear or a helical gear, with their respective rotation axes connected vertically.

[0059] One end of the shaft (320) is connected to the front gear (310) and the other end is connected to the rear gear (330). The rotation axis of the shaft (320) is connected perpendicularly to the rotation axis of the front gear (310) and the rotation axis of the rear gear (330). The longitudinal direction of the rotation axis of the shaft (320) can be positioned horizontally with respect to the direction of travel of the bicycle.

[0060] The rear gear (330) transmits power received from the shaft (320) to the rear wheel. The rear gear (330) may be provided inside the hub of the rear wheel. The rear gear (330) may be provided in a multi-stage type that can adjust the gear ratio.

[0061] According to the example described above, the shaft drive type gear unit (300) is entirely housed inside the housing (100) to minimize external exposure, and has the effect of having superior durability and reduced driving noise compared to the chain type.

[0062] The PAS sensor unit (Pedal Assist System, 400) detects pedaling motion in real time. The PAS sensor unit (400) can transmit the sensed data to the control unit (600). The PAS sensor unit (400) can transmit data to the control unit (600) via wired or wireless communication.

[0063] FIG. 7 is a block diagram showing the PAS sensor unit of FIG. 2. Referring to FIG. 7, the PAS sensor unit (400) includes a torque sensor (410), a rotational speed sensor (420), and an angle sensor (430).

[0064] First, the torque sensor (410) measures the force applied when the rider steps on the pedal (28). The torque sensor (410) is equipped with a strain gauge and can be installed on the crank (27) to which the pedal is connected. That is, the strain gauge can quantify the degree to which the crank (27) is deformed by the force applied by the rider stepping on the pedal as an electrical resistance value.

[0065] The rotational speed sensor (420) detects the rotational speed of the pedal. That is, the rotational speed can measure how fast the rider of the electric bicycle (20) is turning the pedal. The rotational speed sensor (420) is equipped with a non-contact magnetic sensor and can transmit the number of pedal rotations per minute to the control unit (600).

[0066] The angle sensor (430) can detect the angle of the pedal (28) and determine the direction of rotation. The angle sensor (430) can measure whether the direction of rotation of the pedal (28) rotated by the rider is forward or reverse.

[0067] The battery (500) stores and supplies energy required for the electric bicycle (20). It can stably supply power to the drive motor (200) and the control unit (600). The battery (500) may be installed on the outside of the frame (21), but the installation location may change depending on the size of the battery (500) and the shape of the frame (21). For example, the battery (500) may be mounted on the outside of the down tube or seat tube of the bicycle frame (21). In one embodiment of the present invention, the battery (500) may be mounted on the upper part of the down tube to lower the center of gravity of the electric bicycle (20) and improve driving stability. The battery (500) is provided to be detachably mounted on the frame (21), allowing the user to easily charge or replace it.

[0068] The control unit (600) can receive data from the PAS sensor unit (400) and control the output of the battery (500). The control unit (600) according to one embodiment of the present invention can control the output of the battery (500) in proportion to the torque value received from the torque sensor (410). For example, the control unit (600) can control the output of the battery (500) by increasing the degree of intervention of the drive motor (200) as the measured torque value increases.

[0069] In contrast, a control unit (600) according to another embodiment of the present invention can control the output of the battery (500) inversely proportional to the torque value received from the torque sensor (410). That is, when a rider sets the driving speed of the electric bicycle (20) by pressing an output control device (not shown) mounted on the handle (24), the output of the battery can be increased to reach the set driving speed as the torque value is lower.

[0070] Additionally, the control unit (600) can control the output of the battery (500) by referring to the rotational speed of the pedal (28) received from the rotational speed sensor (420). For example, the control unit (600) can control the output of the battery (500) to be lowered when the rotational speed of the pedal (28) is above a preset range, and control the output of the battery (500) to be increased when the rotational speed of the pedal (28) is below a preset range. At this time, the appropriate rotational speed per minute of the pedal (28) may be 80 to 90.

[0071] Additionally, the control unit (600) can control the output of the battery (500) by referring to the rotation direction of the pedal (28) received from the angle sensor (430). For example, the control unit (600) can control the output of the battery (500) to increase when the pedal (28) rotates in the forward direction. That is, when the pedal (28) rotates in the opposite direction, the control unit (600) can determine that the rider has no intention of riding the electric bicycle (20) and control the battery (500) to stop supplying power to the drive motor (200).

[0072] As described above, according to one embodiment of the present invention, external air is introduced into the interior of the housing to cool the drive motor, while preventing moisture from entering, thereby having the effect of increasing the lifespan of the motor.

[0073] In the foregoing, although all components constituting an embodiment of the present invention have been described as being combined or operating in combination, the present invention is not necessarily limited to such embodiments. That is, within the scope of the purpose of the present invention, all such components may be selectively combined in one or more ways to operate. Furthermore, terms such as "include," "constitute," or "have" described above, unless specifically stated otherwise, mean that the relevant component may be inherent; thus, they should be interpreted as allowing for the inclusion of additional components rather than excluding other components. All terms, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains, unless otherwise defined. Terms commonly used, such as those defined in advance, should be interpreted in accordance with their meaning in the context of the relevant technology and, unless explicitly defined in the present invention, should not be interpreted in an ideal or overly formal sense.

[0074] Furthermore, the foregoing description is merely an illustrative explanation of the technical concept of the present invention, and those skilled in the art to which the present invention pertains will be able to make various modifications and variations within the scope of the essential characteristics of the present invention. Accordingly, the embodiments disclosed in the present invention are intended to explain, not limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by such embodiments. The scope of protection of the present invention shall be interpreted by the claims below, and all technical concepts within an equivalent scope shall be interpreted as being included within the scope of rights of the present invention.

Claims

1. In a drive system installed on an electric bicycle to assist pedal power, A housing installed on the crank shaft of the electric bicycle; A drive motor housed inside the above housing and generating driving force; A gear section composed of a plurality of gears connected to the crankshaft and receiving driving force by contacting the drive motor; A PAS sensor unit for detecting pedaling information; and It includes a control unit that controls the output of the drive motor based on the pedaling information received from the PAS sensor unit, and The above housing is, An exhaust section formed in the front and rear directions to discharge heat generated internally; and An electric bicycle drive system having a moisture-proof structure including a moisture-permeable section installed in the exhaust section to block liquid movement and allow gas to pass through.

2. In Paragraph 1, The above exhaust section is, An exhaust hole having a first diameter; and An electric bicycle drive system having a moisture-proof structure including a moisture-permeable groove that is connected to the exhaust hole and is recessed inwardly so that the moisture-permeable part can be installed.

3. In Paragraph 2, The above moisture-permeable groove is, The exhaust hole is formed with a second diameter different from the first diameter, and The above second diameter is, An electric bicycle drive system having a moisture-proof structure formed with a size larger than the first diameter.

4. In Paragraph 3, The above moisture-permeable part is, An electric bicycle drive system having a moisture-proof structure formed such that the outer diameter is larger than the first diameter and equal to or smaller than the second diameter.

5. In Paragraph 2, The above moisture-permeable part is, A moisture-permeable filter formed with a membrane structure that allows gas to pass through while blocking the inflow of liquid; A cover member having a plurality of perforated holes formed therein that prevent the above moisture permeability filter from detaching and communicate with the above exhaust hole; An electric bicycle drive system having a moisture-proof structure including a sealing member provided between the above moisture-permeable filter and the above cover member to block moisture penetration.

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