Electric bicycle driving system having air-guiding heat dissipation structure

Abstract

A driving system installed in an electric bicycle to assist pedal power, according to some embodiments of the present invention, comprises: a housing installed on a crankshaft of the electric bicycle; a driving motor accommodated in the housing to generate a driving force; a heat dissipation unit in contact with the driving motor to dissipate heat generated by the driving motor; a gear unit which is composed of a plurality of gears connected to the crankshaft and is in contact with the driving motor to receive the driving force; a PAS sensor unit which detects pedaling information; and a control unit which controls an output of the driving motor on the basis of the pedaling information received from the PAS sensor unit, wherein the housing has a plurality of through-holes formed therein to draw in or discharge air, and the heat dissipation unit has an air-guiding heat dissipation structure for guiding, in one direction, air introduced into the housing.

Description

Electric bicycle drive system with air-induction heat dissipation structure

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

[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 drive system of an electric bicycle generally includes a battery and a motor. The motor is installed adjacent to the crank in a crank-driven manner and has a structure that generates power by receiving electricity from the battery. Through this, it rotates the crank and performs the role of assisting in riding.

[0006] However, conventional electric bicycle motors have a problem in that they cannot effectively dissipate the heat generated internally during prolonged operation. If the internal temperature of the motor rises due to continuous operation, not only does performance deteriorate, but the motor's durability may also be reduced due to overheating, and in severe cases, it can lead to motor damage. In addition, excessive heat can increase the battery's discharge rate, which shortens usage time.

[0007] Accordingly, we aim to develop an improved electric bicycle motor that enables long-term riding by effectively controlling heat generation.

[0008]

[0009] One objective of the present invention is to provide an electric bicycle drive system having an air-induced heat dissipation structure capable of inducing the direction of airflow.

[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 an air-induced heat dissipation structure according to one embodiment of the present invention is installed on an electric bicycle to assist the power of the pedals, 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 heat dissipation unit in contact with the drive motor to disperse heat generated from the drive motor, a gear unit composed of a plurality of gears connected to the crank shaft and in contact with the drive motor to receive driving force, a PAS sensor unit for detecting pedaling information, and a control unit for controlling the output of the drive motor based on pedaling information received from the PAS sensor unit, wherein the housing has a plurality of through holes formed to inhale or exhale air, and the heat dissipation unit can induce air introduced into the housing in one direction.

[0013] Additionally, the heat dissipation unit may include a plurality of first heat dissipation plates, one side of which is in contact with a drive motor to receive and dissipate heat generated from the drive motor, and a plurality of second heat dissipation plates arranged alternately with the first heat dissipation plates so as to be spaced apart from the plurality of first heat dissipation plates.

[0014] Additionally, the through hole may include a first through hole positioned at the front of the housing to draw in air and a second through hole positioned at the rear of the housing to discharge air.

[0015] In addition, the second heat sink is formed with its upper side curved downward so that it can guide air flowing into the first through hole to the second through hole.

[0016] Additionally, the heat dissipation unit may further include an insulating plate disposed at both ends of a first heat dissipation plate and a second heat dissipation plate, which are provided as a pair and arranged to alternately, and which blocks heat emitted from the first heat dissipation plate from reaching the control unit.

[0017]

[0018] According to an electric bicycle drive system having an air-induced heat dissipation structure according to one embodiment of the present invention, heat generated from the drive motor is directed toward the exhaust port, thereby improving cooling efficiency.

[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 an air-induced heat dissipation 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 an air-induced heat dissipation 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 an air-induced heat dissipation structure according to one embodiment of the present invention.

[0024] FIG. 4 is an exploded perspective view schematically showing the housing, drive motor, and heat dissipation part of FIG. 3.

[0025] Figure 5 is an exploded perspective view schematically showing the heat dissipation part of Figure 4.

[0026] Figure 6 is a schematic diagram showing the airflow in the housing of Figure 3.

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

[0028] Figure 8 is a block diagram showing the PAS sensor section of Figure 2.

[0029]

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] First, an electric bicycle (20) is described in which an electric bicycle drive system (10) having an air-induced heat dissipation structure is installed.

[0035] FIG. 1 is a schematic diagram showing an electric bicycle drive system having an air-induced heat dissipation structure according to one embodiment of the present invention installed on an electric bicycle.

[0036] 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).

[0037] Hereinafter, an electric bicycle drive system (10) having an air-induced heat dissipation structure according to one embodiment of the present invention will be described in detail with reference.

[0038] FIG. 2 is a block diagram of an electric bicycle drive system having an air-induction 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 air-induction heat dissipation structure according to an embodiment of the present invention. FIG. 4 is an exploded perspective view schematically showing the housing, drive motor, and heat dissipation part of FIG. 3.

[0039] Referring to FIGS. 2 to 4, an electric bicycle drive system (10) having an air-induced 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 air-induced 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 (420). As shown in FIG. 2, the electric bicycle drive system (10) having an air-induced heat dissipation structure includes a housing (100), a drive motor (200), a heat dissipation unit (300), a gear unit (400), a PAS sensor unit (500), a battery (600), and a control unit (700).

[0040] The housing (100) can be mounted adjacent to the crankshaft (26). The housing (100) can be provided as a pair and joined on the left and right sides of the frame (21). For example, the housing (100) can be provided with a first housing (100a) and a second housing (100b). That is, the first housing (100a) and the second housing (100b) are joined to form an internal space (S). The housing (100) accommodates a drive motor (200), a heat dissipation unit (300), a gear unit (400), and a control unit (700) in the internal space (S). The housing (100) protects the drive motor (200), the heat dissipation unit (300), the gear unit (400), and the control unit (700) from external foreign matter. Additionally, the housing (100) may be formed to cover the shaft (420) described later and the sprocket (not shown) coupled to the rear wheel. The housing (100) may be formed of a metal or synthetic resin material.

[0041] The housing (100) has a plurality of through holes (101) formed therein to discharge heat generated from the drive motor (200) housed inside. The through holes (101) are formed at the front and rear of the housing (100) to draw air into the housing (100) or to discharge air from inside the housing (100). At this time, if the first through hole (101a) formed at the front of the housing (100) is located adjacent to the front or bottom surface of the housing (100), foreign matter splashing up from the ground may enter, and the motor performance may be degraded. Therefore, it is preferable that the first through hole (101a) be formed to face upward rather than the direction of travel of the electric bicycle (20).

[0042] The drive motor (200) is provided in the internal space (S) of the housing (100). The drive motor (200) receives electrical energy from the battery (600), 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).

[0043] The stator is electrically connected to the battery (600). The stator is in the form of a coil wound multiple times, and current supplied from the battery (600) passes through it to generate a magnetic field.

[0044] 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 (400) to transmit rotational mechanical energy to the gear unit (400).

[0045] 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 through hole (101) of the housing (100).

[0046] A heat dissipation unit (300) is provided in the internal space (S) of the housing (100). One surface of the heat dissipation unit (300) is in contact with the drive motor (200). The heat dissipation unit (300) receives and releases heat generated from the drive motor (200). Additionally, the heat dissipation unit (300) can guide air introduced into the housing (100) in one direction. For example, the heat dissipation unit (300) can guide air introduced into the first through hole (101a) of the housing (100) toward the second through hole (101b) formed at the rear of the housing (100).

[0047] FIG. 5 is an exploded perspective view schematically showing the heat dissipation unit of FIG. 4. Referring to FIG. 5, the heat dissipation unit (300) includes a first heat dissipation plate (301) and a second heat dissipation plate (302). The first heat dissipation plate (301) and the second heat dissipation plate (302) may each be provided in multiple numbers. The heat dissipation unit (300) according to one embodiment of the present invention may be formed in a structure in which the first heat dissipation plate (301) and the second heat dissipation plate (302) are arranged alternately in one direction.

[0048] The first heat sink (301) receives and dissipates heat generated from the drive motor (200). The first heat sink (301) is formed with a larger surface area than the second heat sink (302) to dissipate heat. For example, the first heat sink (301) may be formed with a size that can fill the remaining area of ​​the internal space (S) of the housing (100), excluding the drive motor (200) and the gear part (400). The first heat sink (301) may be formed from a metal material with high thermal conductivity. For example, the heat dissipation part (300) may be made of an aluminum alloy or a copper alloy material.

[0049] The first heat sink (301) can generate vortices in the air passing between the plurality of first heat sinks (301) to improve the heat dissipation efficiency of the drive motor (200). A plurality of protrusions (not shown) may be formed on the first heat sink (301) to increase the contact time between the first heat sink (301) and the air. The plurality of protrusions may be formed on at least one of the two sides of the first heat sink (301). In this case, if the plurality of protrusions are formed on both sides of the first heat sink (301), the protrusions formed on one of the first heat sinks (301) may be formed in the same number as the protrusions formed on the adjacent first heat sink (301) and may be placed in an overlapping position. When the protrusions are formed overlapping each other on the first heat sink (310), the overlapping protrusions may be formed to have different sizes.

[0050] The second heat sink (302) is positioned between one first heat sink (301a) and an adjacent first heat sink (301b) to separate the first heat sink (301a) and the first heat sink (301b). The second heat sink (302) is formed with a narrower surface area than the first heat sink (301) to increase the surface area of ​​the first heat sink (301) in contact with air. The second heat sink (302) may be formed from the same material as the first heat sink (301). The second heat sink (302) may be formed integrally with the first heat sink (301).

[0051] According to the example described above, the first through hole (101a) and the second through hole (101b) are arranged at an obtuse angle, so that air flowing into the internal space (S) of the housing (100) through the first through hole (101a) hits the wall and a vortex is generated, and there is a problem that the heat dissipation efficiency of the drive motor (200) is lowered.

[0052] To solve this, a second heat dissipation plate (302) according to one embodiment of the present invention can guide the direction of air flow into the housing (100). More specifically, the second heat dissipation plate (302) can be formed in a shape that guides the air flowing into the first through hole (101a) toward the direction in which the second through hole (101b) is formed. At this time, the second heat dissipation plate (302) can be formed such that one end faces the first through hole (101a) and the other end faces the second through hole (101b). In addition, the second heat dissipation plate (302) can be formed in a curved shape in one direction to minimize the occurrence of vortices when the air flowing into the housing moves from the first through hole (101a) to the second through hole (101b) formed at a different angle or in a different direction.

[0053] FIG. 6 is a schematic diagram showing the airflow in the housing of FIG. 3. Referring to FIG. 6, a second heat sink (302) according to one embodiment of the present invention is formed with a downwardly curved surface from the first through hole (101a) to the second through hole (101b) so as to guide the air flowing into the first through hole (101a) toward the second through hole (101b).

[0054] According to the example described above, when air introduced from the front upper side of the housing (100) passes between a plurality of first heat dissipation plates (301) of the heat dissipation unit (300), turbulence is generated by the protrusions formed on the first heat dissipation plates (301), thereby improving heat dissipation efficiency, and the upper side of the second heat dissipation plate (302) is formed as a curved surface, thereby changing the turbulence into laminar flow and relieving air stagnation.

[0055] The heat dissipation unit (300) may further include insulation plates (303) at both ends of the first heat dissipation plate (301) and the second heat dissipation plate (302) which are arranged alternately. The insulation plates (303) block heat emitted from the first heat dissipation plate (301) from being emitted into the internal space (S) of the housing (100). More specifically, the insulation plates (303) may block heat emitted through the first heat dissipation plate (301) from reaching the control unit (700). The width of the insulation plates (303) may be formed to be equal to or larger than that of the first heat dissipation plate (301). Additionally, the insulation plates (303) may be formed from a material with low thermal conductivity. Furthermore, the insulation plates (303) may be formed with a thickness greater than that of the first heat dissipation plate (301).

[0056] At this time, a plurality of fixing pins (not shown) or side supports (not shown) in the longitudinal direction may be installed to fix the insulation plate (303) to the first heat dissipation plate (301) and the second heat dissipation plate (302).

[0057] The gear unit (400) is provided in the internal space (S) of the housing (100). The gear unit (400) is mechanically connected to the drive motor (200). The gear unit (400) receives power from the drive motor (200) and rotates the wheel (25). Hereinafter, the gear unit (400) is described as transmitting power from the drive motor (200) to the rear wheel in a shaft drive manner. FIG. 7 is a block diagram showing the gear unit of FIG. 2. Referring to FIG. 7, the gear unit (400) includes a front gear (410), a shaft (420), and a rear gear (430).

[0058] First, one side of the front gear (410) 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 (420). At this time, the front gear (410), shaft (420), and rear gear (430) 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 (420) is connected to the front gear (410) and the other end is connected to the rear gear (430). The rotation axis of the shaft (420) is connected perpendicularly to the rotation axis of the front gear (410) and the rotation axis of the rear gear (430). The longitudinal direction of the rotation axis of the shaft (420) can be positioned horizontally with respect to the direction of travel of the bicycle.

[0060] The rear gear (430) transmits power received from the shaft (420) to the rear wheel. The rear gear (430) may be provided inside the hub of the rear wheel. The rear gear (430) 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 (400) 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 (500) can transmit the sensed data to the control unit (700). The PAS sensor unit (500) can transmit data to the control unit (700) via wired or wireless communication.

[0063] FIG. 8 is a block diagram showing the PAS sensor unit of FIG. 2. Referring to FIG. 8, the PAS sensor unit (500) includes a torque sensor (510), a rotational speed sensor (520), and an angle sensor (530).

[0064] First, the torque sensor (510) measures the force applied when the rider steps on the pedal (28). The torque sensor (510) 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 (520) 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 (520) is equipped with a non-contact magnetic sensor and can transmit the number of pedal rotations per minute to the control unit (700).

[0066] The angle sensor (530) can detect the angle of the pedal (28) and determine the direction of rotation. The angle sensor (530) can measure whether the direction of rotation of the pedal (28) rotated by the rider is forward or reverse.

[0067] The battery (600) stores and supplies energy required for the electric bicycle (20). It can stably supply power to the drive motor (200) and the control unit (700). The battery (600) may be installed on the outside of the frame (21), but the installation location may change depending on the size of the battery (600) and the shape of the frame (21). For example, the battery (600) 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 (600) 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 (600) is provided to be detachably mounted on the frame (21), allowing the user to easily charge or replace it.

[0068] The control unit (700) can receive data from the PAS sensor unit (500) and control the output of the battery (600). The control unit (700) according to one embodiment of the present invention can control the output of the battery (600) in proportion to the torque value received from the torque sensor (510). For example, the control unit (700) can control the output of the battery (600) by increasing the degree of intervention of the drive motor (200) as the measured torque value increases.

[0069] In contrast, a control unit (700) according to another embodiment of the present invention can control the output of the battery (600) inversely proportional to the torque value received from the torque sensor (510). 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 (700) can control the output of the battery (600) by referring to the rotational speed of the pedal (28) received from the rotational speed sensor (520). For example, the control unit (700) can control the output of the battery (600) to be lowered when the rotational speed of the pedal (28) is above a preset range, and control the output of the battery (600) 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 (700) can control the output of the battery (600) by referring to the rotational direction of the pedal (28) received from the angle sensor (530). For example, the control unit (700) can control the output of the battery (600) 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 (700) can determine that the rider has no intention of riding the electric bicycle (20) and control the battery (600) to stop supplying power to the drive motor (200).

[0072] As described above, according to one embodiment of the present invention, when air introduced into the internal space of the housing through the first through hole moves to the second through hole arranged at a different angle from the first through hole, it moves along the second heat sink, thereby improving the flow of air.

[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 heat dissipation part that contacts the above-mentioned drive motor and disperses heat generated from the above-mentioned drive motor; 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 through holes are formed to draw in or expel air, and The above heat dissipation unit is, An electric bicycle drive system having an air-induced heat dissipation structure that directs air introduced into the housing in one direction.

2. In Paragraph 1, The above heat dissipation unit is, A plurality of first heat sinks, one side of which is in contact with the drive motor to receive and dissipate heat generated from the drive motor; and An electric bicycle drive system having an air-induced heat dissipation structure comprising a plurality of second heat dissipation plates arranged alternately with the first heat dissipation plates so as to be spaced apart from the plurality of first heat dissipation plates.

3. In Paragraph 2, The above through hole is, A first through hole positioned at the front of the above housing to draw in air; and An electric bicycle drive system having an air-induced heat dissipation structure including a second through hole disposed at the rear of the housing to discharge air.

4. In Paragraph 3, The above second heat sink is, An electric bicycle drive system having an air-induction type heat dissipation structure that guides air introduced into the first through hole to the second through hole.

5. In Paragraph 2, The above heat dissipation unit is, An electric bicycle drive system having an air-induced heat dissipation structure, further comprising an insulating plate disposed at both ends of the first heat dissipation plate and the second heat dissipation plate, which are provided as a pair and arranged to alternately, and which blocks heat emitted from the first heat dissipation plate from reaching the control unit.

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