Electric bicycle driving system having adjustable heat dissipation structure

Abstract

The purpose of the present invention is to provide an electric bicycle driving system having an adjustable heat dissipation structure, the driving system being installed on an electric bicycle to supplement the power of pedals, and comprising: a housing installed on a crankshaft of the electric bicycle; a driving motor accommodated inside the housing to generate a driving force; a gear unit that comprises a plurality of gears connected to the crankshaft and comes into contact with the driving motor and receives the driving force; a PAS sensor unit that senses pedaling information; and a control unit that controls the output of the driving motor on the basis of the pedaling information received from the PAS sensor unit, wherein the housing includes a cooling hole, formed in the front-rear direction to discharge heat generated therein, and a variable cooling element, installed in the cooling hole to regulate the flow rate of air flowing into the housing.

Description

Electric bicycle drive system with adjustable heat dissipation structure

[0001] The present invention relates to an electric bicycle drive system having an adjustable heat dissipation structure, and more specifically, to an electric bicycle drive system having an adjustable heat dissipation structure capable of easily dissipating heat generated from a motor.

[0002] 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.

[0003] 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.

[0004] 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.

[0005] However, the heat dissipation structure of conventional electric motors allows for the effective expulsion of hot internal air to the outside while simultaneously allowing external air to flow back in, which can lead to reduced heat dissipation performance. This hinders proper control of the internal temperature of the motor, raising concerns about performance degradation or damage due to overheating during prolonged use.

[0006] To solve this problem, it is required to develop an electric motor with a heat dissipation structure capable of effectively dissipating heat generated internally.

[0007] One objective of the present invention is to provide an electric bicycle drive system having an adjustable heat dissipation structure capable of controlling the opening rate of cooling holes.

[0008] 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.

[0009] An electric bicycle drive system having an adjustable heat dissipation 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 unit composed of a plurality of gears connected to the crank shaft and receiving driving force in contact with the drive motor, a PAS sensor unit that detects pedaling information, and a control unit that controls the output of the drive motor based on pedaling information received from the PAS sensor unit, wherein the housing may include a plurality of cooling holes that discharge heat generated inside and a variable cooling unit installed in the cooling holes to regulate the flow rate of air entering the housing.

[0010] Additionally, the variable cooling unit may include a body having a plurality of through holes formed on its side and configured to be movable with one end connected to a cooling hole, a flow control unit configured inside a housing to move the body in the longitudinal direction, and a foreign matter prevention cap connected to the other end of the body to block foreign matter from entering the cooling hole.

[0011] In addition, the housing may further include a cooling groove formed inwardly that communicates with the cooling hole and is connected to the inside, and a vortex generating part provided in the cooling groove to generate a vortex in the air flowing into the cooling hole.

[0012] In addition, the foreign matter prevention cap may be formed in the shape of a disc that is concave inwardly, and may have an outer diameter that is larger than the cooling hole and smaller than the cooling groove.

[0013] In addition, the vortex generating part may include a hole connecting part that is inserted and fixed into a cooling hole and a flow forming part that guides the direction of the incoming air.

[0014] In addition, the flow forming part may have a stepped portion protruding in an area adjacent to the hole connecting part, and the stepped portion may generate a vortex in the air flowing into the cooling hole so that a portion is discharged.

[0015] According to an electric bicycle drive system having an adjustable heat dissipation structure according to one embodiment of the present invention, the opening rate of the cooling hole is adjusted according to the internal temperature of the housing, thereby improving the driving efficiency of the motor provided inside the housing for the electric bicycle.

[0016] 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.

[0017] FIG. 1 is a schematic diagram showing an electric bicycle drive system having an adjustable heat dissipation structure according to one embodiment of the present invention installed on an electric bicycle.

[0018] FIG. 2 is a block diagram of an electric bicycle drive system having an adjustable heat dissipation structure according to one embodiment of the present invention.

[0019] FIG. 3 is a perspective view schematically showing a part of an electric bicycle and an electric bicycle having an adjustable heat dissipation structure according to one embodiment of the present invention.

[0020] Fig. 4 is a front view of the housing of Fig. 3.

[0021] FIG. 5 is an exploded perspective view of a housing according to one embodiment of the present invention.

[0022] FIG. 6 is a cross-sectional view schematically showing a housing according to one embodiment of the present invention.

[0023] FIG. 7 is an exploded perspective view of a housing according to another embodiment of the present invention.

[0024] FIG. 8 is a cross-sectional view schematically showing a housing according to another embodiment of the present invention.

[0025] FIG. 9 is a schematic diagram showing the airflow in a variable cooling unit and a vortex generating unit according to one embodiment of the present invention.

[0026] Figure 10 is a block diagram showing the gear section of Figure 2.

[0027] FIG. 11 is a block diagram showing the PAS sensor section of FIG. 2.

[0028] 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.

[0029] Identical reference numbers or symbols presented 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.

[0030] 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.

[0031] 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.

[0032] First, an electric bicycle (20) is described in which an electric bicycle drive system (10) having an adjustable heat dissipation structure is installed.

[0033] FIG. 1 is a schematic diagram showing an electric bicycle drive system having an adjustable heat dissipation structure according to one embodiment of the present invention installed on an electric bicycle.

[0034] 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 an adjustable heat dissipation structure provided adjacent to the crank shaft (26) in the frame (21).

[0035] Hereinafter, an electric bicycle drive system (10) having an adjustable heat dissipation structure according to one embodiment of the present invention will be described in detail with reference.

[0036] FIG. 2 is a block diagram of an electric bicycle drive system having an adjustable heat dissipation 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 an adjustable heat dissipation structure according to an embodiment of the present invention. FIG. 4 is a front view of the housing of FIG. 3.

[0037] Referring to FIGS. 2 to 4, an electric bicycle drive system (10) having an adjustable heat dissipation 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 an adjustable heat dissipation structure may be a shaft drive type that transmits power from a drive motor (200) to a wheel using a vertically connected shaft (320). As shown in FIG. 2, the electric bicycle drive system (10) having an adjustable heat dissipation 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).

[0038] The housing (100) can be mounted adjacent to the crankshaft (26). The housing (100) has an internal space formed to accommodate a drive motor (200), a gear unit (300), and a control unit (600) inside. The housing (100) protects the drive motor (200), the gear unit (300), and the control unit (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.

[0039] A plurality of cooling holes (101) are formed in the housing (100). The cooling holes (101) are formed at the front and rear of the housing (100) to discharge heat generated from the drive motor (200) housed inside the housing (100). The cooling holes (101) are formed in a circular shape and may have a first diameter (D1).

[0040] Additionally, a cooling groove (102) is formed in the housing (100). The cooling groove (102) is formed as a space in which the variable cooling unit (110) and the vortex generating unit (120), which will be described later, are arranged. The cooling groove (102) is formed to be drawn inward from the outer surface of the housing (100). The cooling groove (102) is arranged to communicate with the cooling hole (101). The cooling groove (102) is formed at a position that overlaps with the cooling hole (101). The cooling groove (102) is formed in a circular shape and may have a second diameter (D2) that is different from the first diameter (D1) of the cooling hole (101). For example, the second diameter (D2) of the cooling groove (102) may be formed to be larger than the first diameter (D1) of the cooling hole (101).

[0041] The housing (100) includes a variable cooling unit (110) that is inserted into the cooling hole (101) and controls the amount of air flowing in or out.

[0042] FIG. 5 is an exploded perspective view of a housing according to one embodiment of the present invention. FIG. 6 is a cross-sectional view schematically showing a housing according to one embodiment of the present invention.

[0043] Referring to FIGS. 5 and 6, the variable cooling unit (110) includes a body (111), a flow rate control unit (112), and a foreign matter prevention cap (113).

[0044] The body (111) is inserted into the cooling hole (101) in a cylindrical shape. The body (111) is configured to be movable in the longitudinal direction while inserted into the cooling hole (101). The body (111) is formed such that its outer surface contacts the inner surface of the cooling hole (101), thereby preventing air from moving between the body (111) and the cooling hole (101). The body (111) may have a plurality of through holes (1111) formed on its side through which air can move.

[0045] The through holes (1111) are formed along the longitudinal direction of the body (111). Multiple through holes (1111) may be formed with the same size and arranged at equal intervals. However, the through holes (1111) are not limited to this and may be formed with a smaller size as they are spaced further from the foreign matter prevention cap (113).

[0046] The flow control unit (112) controls the flow rate of air flowing into or out of the cooling hole (101). The flow control unit (112) is provided inside the housing (100) and connected to the body (111). The flow control unit (112) can move the body (111) in the longitudinal direction. The flow control unit (112) can control the depth to which the body (111) is inserted into the cooling hole (101). Specifically, the flow control unit (112) can control the flow rate of air by moving the body (111) to the inside or outside of the cooling hole (101) and controlling the number of exposed through holes (1111). As an example, the flow control unit (112) may be provided as an actuator that moves the body (111) in the longitudinal direction.

[0047] The foreign matter prevention cap (113) is positioned on the inner side of the cooling groove (102) to block foreign matter exceeding a preset size from entering the cooling hole (101). The foreign matter prevention cap (113) is coupled to the other side of the body (111), one side of which is connected to the cooling hole (101). The foreign matter prevention cap (113) may be formed integrally with the body (111). That is, the foreign matter prevention cap (113) blocks the other end of the body (111), one end of which is inserted into the cooling hole (101), thereby guiding the air flowing into or out of the cooling hole (101) to move only to the through hole (1111) formed on the side of the body (111).

[0048] The foreign matter prevention cap (113) may be formed in the shape of a disc that is concave inwardly. The outer circumference of the foreign matter prevention cap (113) may be spaced apart from the inner side of the cooling groove (102) by a predetermined distance. That is, the outer diameter of the foreign matter prevention cap (113) may be formed as a third diameter (D3) that is larger than the first diameter (D1) and smaller than the second diameter (D2).

[0049] FIG. 7 is an exploded perspective view of a housing according to another embodiment of the present invention. FIG. 8 is a cross-sectional view schematically showing a housing according to another embodiment of the present invention.

[0050] Referring to FIGS. 7 and 8, the housing (100) further includes a vortex generating part (120).

[0051] The vortex generating unit (120) generates a vortex in the air flowing into the cooling hole (101) to regulate the amount of air flowing in and to block the entry of foreign substances. The vortex generating unit (120) is configured to communicate with the cooling hole (101) so that air can move. The vortex generating unit (120) includes a hole connecting unit (121) and a flow forming unit (122).

[0052] The hole connecting part (121) is positioned between the body (111) and the cooling hole (101). The hole connecting part (121) allows the vortex generating part (120) to be fixed to the cooling hole (101). The hole connecting part (121) is formed in a cylindrical shape with an outer diameter corresponding to the first diameter (D1) of the cooling hole (101) and can be fixed by fitting. At this time, the body (111) can be formed such that its outer surface contacts the inner surface of the hole connecting part (121). However, the body (111) is not coupled to the hole connecting part (121) by fitting, but can be provided to be movable along the longitudinal direction.

[0053] The flow forming part (122) is positioned inside the cooling groove (102). The flow forming part (122) guides the direction of the incoming air. The flow forming part (122) may be formed in a truncated cone shape such that the opening widens as it moves away from the hole connecting part (121). According to the example described above, the incoming air can form a flow in a diagonal direction to guide the flow of air into the through hole (1111).

[0054] The flow forming part (122) generates a vortex in the incoming air. The flow forming part (122) may have a stepped part (1221) protruding upward in an area adjacent to the hole connecting part (121). That is, the flow forming part (122) generates a vortex in a portion of the incoming air by the stepped part (1221) so that it is discharged.

[0055] FIG. 9 is a schematic diagram showing the airflow in a variable cooling unit and a vortex generating unit according to one embodiment of the present invention.

[0056] Referring to FIG. 9, some of the air introduced into the vortex generating part (120) forms a vortex by the step part (1221) and is exhausted between the foreign matter prevention cap (113) and the cooling groove (102), thereby forming an air curtain that blocks the inflow of foreign matter, and has the effect of controlling the amount of air introduced into the cooling hole (101).

[0057] 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).

[0058] 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.

[0059] 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).

[0060] 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 variable cooling unit (110) of the housing (100).

[0061] 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. 10 is a block diagram showing the gear unit of FIG. 2. Referring to FIG. 10, the gear unit (300) includes a front gear (310), a shaft (320), and a rear gear (330).

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] FIG. 11 is a block diagram showing the PAS sensor unit of FIG. 2. Referring to FIG. 11, the PAS sensor unit (400) includes a torque sensor (410), a rotational speed sensor (420), and an angle sensor (430).

[0068] 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.

[0069] 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).

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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).

[0076] Additionally, the control unit (600) can control the operation of the flow control unit (112). For example, the control unit (600) can control the flow control unit (112) to move the body (111) outwardly toward the housing to increase the amount of air sucked into the housing (100) when the temperature of the drive motor (200) is above a preset temperature.

[0077] Additionally, the control unit (600) can control the flow control unit (112) to move the body (111) inwardly toward the housing in order to reduce the amount of air sucked into the housing (100) when the temperature of the drive motor (200) is below a preset temperature.

[0078]

[0079] As described above, according to one embodiment of the present invention, if the temperature of the drive motor (200) is higher than the appropriate temperature, the resistance of the circuit increases, and if the temperature of the motor is lower than the appropriate temperature, the material shrinks, which may cause a problem affecting performance. Accordingly, the flow rate control unit (112) can adjust the number of exposed through holes (1111) by adjusting the position where the body (111) is inserted into the cooling hole (101), thereby changing the amount of air flowing into or out of the housing (100) to a preset amount, which has the effect of maintaining the performance of the drive motor (200) in an optimal state.

[0080] In addition, the foreign matter prevention cap (113) and the vortex generating part (120) block foreign matter flowing into the cooling hole (101), thereby preventing a decrease in exhaust performance.

[0081]

[0082] 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.

[0083] 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, Multiple cooling holes for discharging heat generated internally; and An electric bicycle drive system having an adjustable heat dissipation structure including a variable cooling unit installed in the cooling hole to regulate the flow rate of air entering the housing.

2. In Paragraph 1, The above variable cooling unit is, A body having a plurality of through holes formed on its side and configured to be movable with one end connected to the cooling hole; A flow control unit provided inside the above housing and moving the body in the longitudinal direction; and An electric bicycle drive system having an adjustable heat dissipation structure including a foreign matter prevention cap connected to the other end of the body to block foreign matter from entering the cooling hole.

3. In Paragraph 2, The above housing is, A cooling groove is formed that communicates with the above-mentioned cooling hole and is drawn inward, and An electric bicycle drive system having an adjustable heat dissipation structure, further comprising a vortex generating part provided in the cooling groove and generating a vortex in the air flowing into the cooling hole.

4. In Paragraph 3, The above foreign matter prevention cap is, An electric bicycle drive system having an adjustable heat dissipation structure formed such that the outer diameter is larger than the cooling hole and smaller than the cooling groove.

5. In Paragraph 3, The above vortex generating unit is, A hole connecting part inserted and fixed in a cooling hole; and An electric bicycle drive system having a heat dissipation structure including a flow forming part that guides the direction of incoming air.

6. In Paragraph 5, The above flow forming part is, A stepped portion is formed protrudingly in an area adjacent to the above-mentioned hole connection portion, and The above-mentioned stepped portion is, An electric bicycle drive system having an adjustable heat dissipation structure that generates a vortex in the air flowing into the cooling hole to allow a portion of it to be discharged. blanket

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