Middle motor and power-assisted bicycle

Abstract

The utility model provides a middle motor and a moped, and relates to the technical field of mopeds. The middle motor comprises a driving device with a driving shaft, a transmission device comprising a fixed gear ring, a movable gear ring, a sun gear and a plurality of planet gears, and an output device comprising an output shaft, a first rotating part, a second rotating part, a first clutch and a second clutch. The sun gear is connected with the driving shaft, the multiple planet gears are arranged in the circumferential direction of the sun gear at intervals, each planet gear is meshed with the sun gear, the fixed gear ring and the movable gear ring, the output shaft is connected with the movable gear ring, and the first rotating part rotationally penetrates through the driving shaft, the sun gear, the fixed gear ring, the movable gear ring, the output shaft and the second rotating part and is coaxially arranged. The first clutch is arranged between the first rotating piece and the output shaft, and the second clutch is arranged between the second rotating piece and the output shaft. According to the middle motor provided by the invention, a coaxial design and a planetary speed reduction structure are adopted, and large speed ratio, miniaturization and light weight are taken into account.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of power-assisted bicycles, and particularly relates to a middle motor and a power-assisted bicycle. BACKGROUND

[0002] The information disclosed in this Background section is only for the purpose of enhancing the understanding of the general background of the present disclosure and does not necessarily constitute prior art that is already known to a person skilled in the art.

[0003] A power-assisted bicycle is a new type of transportation tool capable of realizing the integration of human-powered riding and motor assistance. A motor installed in the middle position of the body of the power-assisted bicycle is called a middle motor, which is connected with the wheels of the power-assisted bicycle to provide assistance. Meanwhile, pedals of the power-assisted bicycle are installed on both sides of the middle motor, so that users can realize human-powered riding in the case that the middle motor has no power supply. In the related art, the middle motor used by the power-assisted bicycle adopts a three-stage parallel gear transmission structure, which has the problem of being difficult to balance large speed ratio and miniaturization. CONTENT OF THE UTILITY MODEL

[0004] Therefore, the present application aims to provide a middle motor and a power-assisted bicycle, which aims to solve the technical problem of the middle motor being difficult to balance large speed ratio and miniaturization in the related art.

[0005] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0006] In a first aspect, the embodiments of the present application provide a middle motor applied to a power-assisted bicycle with pedals and wheels, and the middle motor comprises:

[0007] A driving device with a driving shaft;

[0008] A transmission device comprising a fixed ring gear, a movable ring gear, a sun gear and a plurality of planet gears, the sun gear being connected with the driving shaft, the plurality of planet gears being arranged at intervals along the circumferential direction of the sun gear, and each planet gear being engaged with the sun gear, the fixed ring gear and the movable ring gear, respectively;

[0009] The output device comprises an output shaft, a first rotating member and a second rotating member, the output shaft is connected with the movable ring gear, the first rotating member is rotatably arranged through the driving shaft, the sun gear, the fixed ring gear, the movable ring gear, the output shaft and the second rotating member respectively, the first rotating member, the driving shaft, the sun gear, the fixed ring gear, the movable ring gear, the output shaft and the second rotating member are coaxially arranged, the output device further comprises a first clutch and a second clutch, the first clutch is arranged between the first rotating member and the output shaft, the second clutch is arranged between the second rotating member and the output shaft, the first rotating member is used for connecting the pedal, and the second rotating member is used for connecting the wheel.

[0010] In one of the embodiments of the first aspect, the transmission device further comprises a planet carrier, the first rotating member and the driving shaft are rotatably arranged through the planet carrier respectively, and the first rotating member and the planet carrier are coaxially arranged, each of the planet gears is rotatably arranged on the planet carrier.

[0011] In one of the embodiments of the first aspect, at least one of the sun gear, the planet carrier and the fixed ring gear is integrally formed by using a plastic material.

[0012] In one of the embodiments of the first aspect, the plastic material is polyether ether ketone.

[0013] In one of the embodiments of the first aspect, each of the planet gears is rotatably connected with the planet carrier through a connecting shaft, each of the planet gears comprises a connecting portion, a first gear portion and a second gear portion, the connecting shaft is rotatably arranged through the connecting portion, the first gear portion and the second gear portion are coaxially arranged and respectively arranged on the outer circumferential side of the connecting portion, the first gear portion is engaged with the sun gear and the fixed ring gear respectively, and the second gear portion is engaged with the movable ring gear.

[0014] In one of the embodiments of the first aspect, the transmission device further comprises a first bearing, an outer ring of the first bearing is connected with the connecting portion, an inner ring of the first bearing is connected with the connecting shaft, and the first bearing is a retainer needle bearing.

[0015] In one of the embodiments of the first aspect, the planet carrier comprises a first planet carrier body and a second planet carrier body which are coaxially arranged, each of the planet gears is rotatably connected between the first planet carrier body and the second planet carrier body, at least part of the first planet carrier body is located in a first through hole of the fixed ring gear, and at least part of the second planet carrier body is located in a second through hole of the movable ring gear.

[0016] In one of the embodiments of the first aspect, the sun gear and the outer circumferential side of the first rotating member have a first floating gap; and / or, the outer circumferential side of the planet carrier and the drive shaft have a second floating gap.

[0017] In one of the embodiments of the first aspect, the middle motor further comprises a housing, the housing comprises a first shell, a second shell and a third shell, the second shell is connected between the first shell and the second shell, the first shell, the second shell and the third shell enclose a containing cavity, the drive device and the transmission device are located in the containing cavity, the output shaft is located in the containing cavity, at least part of the first rotating member is located in the containing cavity, at least part of the second rotating member is located in the containing cavity, and the fixed ring gear is fixedly connected with the second shell.

[0018] In the second aspect, the embodiments of the present application provide a power-assisted bicycle, comprising a vehicle body, a vehicle wheel, a pedal, a crank, a sprocket and the middle motor in any one of the embodiments of the first aspect, the middle motor and the vehicle wheel are arranged on the vehicle body respectively, the crank is connected between the first rotating member and the pedal, and the sprocket is connected between the second rotating member and the vehicle wheel.

[0019] The beneficial effects of the present application are as follows:

[0020] The middle motor provided by the present application adopts the planetary reduction structure as the transmission device, so that the transmission device has the characteristic of large transmission speed ratio, and on this basis, the first rotating member connected with the pedal is rotatably arranged on the drive shaft, the sun gear, the fixed ring gear, the movable ring gear, the output shaft and the second rotating member connected with the vehicle wheel, and the first rotating member, the drive shaft, the sun gear, the fixed ring gear, the movable ring gear, the output shaft and the second rotating member are coaxially arranged, so as to reduce the radial dimension and the axial dimension of the middle motor, and the structure is more compact, so that the middle motor has both large speed ratio and miniaturization.

[0021] In order to make the above-mentioned purposes, characteristics and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments, and it should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope, and for those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0023] Figure 1A perspective view of the structure of the middle motor is shown in one embodiment of the present application.

[0024] Figure 2 Another perspective view of the structure of the middle motor is shown in one embodiment of the present application.

[0025] Figure 3 A perspective view of the structure of the middle motor is shown in one embodiment of the present application. Figure 2 A cross-sectional view of the structure of the middle motor is shown at A-A.

[0026] Figure 4 A perspective view of the structure of the middle motor is shown in one embodiment of the present application.

[0027] Figure 5 A perspective view of the structure of the middle motor is shown in one embodiment of the present application. Figure 4 An exploded view of the structure of the middle motor is shown in one embodiment of the present application.

[0028] Figure 6 A perspective view of the structure of the transmission is shown in one embodiment of the present application.

[0029] Figure 7 Another perspective view of the structure of the transmission is shown in one embodiment of the present application.

[0030] Figure 8 A perspective view of the structure of the transmission is shown in one embodiment of the present application.

[0031] Figure 9 Another perspective view of the structure of the transmission is shown in one embodiment of the present application.

[0032] Figure 10 Another perspective view of the structure of the transmission is shown in one embodiment of the present application.

[0033] Figure 11 An exploded view of the structure of the middle motor is shown in one embodiment of the present application.

[0034] Explanation of main component symbols:

[0035] 100 - electric machine; 110 - driving device; 111 - driving shaft; 1111 - second floating gap; 1112 - spline hole; 112 - stator; 113 - rotor; 114 - fourth bearing; 115 - fifth bearing; 120 - transmission device; 121 - fixed ring gear; 1211 - first through hole; 122 - movable ring gear; 1221 - second through hole; 123 - sun gear; 1231 - bevel gear; 124 - planet gear; 1241 - connecting part; 1242 - first gear part; 1243 - second gear part; 125 - planet carrier; 1251 - first planet carrier body; 1252 - second planet carrier body; 126 - connecting shaft; 127 - first bearing; 128 - second bearing; 129 - third bearing; 130 - output device; 131 - output shaft; 132 - first rotating member; 1321 - first floating gap; 133 - second rotating member; 134 - first clutch; 135 - second clutch; 136 - sixth bearing; 137 - seventh bearing; 140 - housing; 141 - first housing; 142 - second housing; 143 - third housing; 144 - accommodating cavity; X - axial; Y - radial; Z - circumferential. DETAILED DESCRIPTION

[0036] Embodiments of the present application are described below in detail, examples of which are shown in the accompanying drawings, wherein the same or similar notations represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the accompanying drawings are exemplary, only for explaining the present application, and cannot be understood as a limitation of the present application.

[0037] In the description of the present application, the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like is based on the orientation or positional relationship shown in the drawings, only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0038] In addition, unless specifically stated and limited otherwise, the first feature "on" or "under" the second feature can be that the first feature and the second feature are in direct contact, or the first feature and the second feature are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0039] In the description of the present application, the terms "first", "second" and the like are used to distinguish different objects, and cannot be understood as indicating or implying a specific order or primary and secondary relationship, or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0040] In the description of the present application, unless otherwise specifically stated and limited, the terms "mounting", "connection", "connection", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0041] In the description of the present application, the term "and / or" indicates that there can be three relationships, for example, A and / or B, which can represent the following three cases: A exists alone, A and B exist together, and B exists alone. In addition, the character " / ", in general, indicates that the front and rear associated objects are in an "or" relationship.

[0042] In the description of the present application, "parallel" not only includes the case of absolute parallel, but also includes the case of approximate parallel which is generally recognized in engineering; at the same time, "vertical" not only includes the case of absolute vertical, but also includes the case of approximate vertical which is generally recognized in engineering. Illustratively, the included angle between two directions is 80°-90°, which can be considered as vertical; the included angle between two directions is 0°-10°, which can be considered as parallel.

[0043] The power-assisted bicycle is a new type of transportation tool capable of realizing the integration of human riding and motor assistance. The motor installed in the middle position of the power-assisted bicycle body is called a middle motor, which is connected with the wheels of the power-assisted bicycle to assist, and the pedals of the power-assisted bicycle are installed on both sides of the middle motor. In the case that the middle motor has no power supply, the user can realize human riding through the pedals.

[0044] In the related art, the middle motor used by the power-assisted bicycle adopts a three-stage parallel gear transmission structure, which has the problem of being difficult to balance large speed ratio, miniaturization and light weight. In addition, the inventor found that the planetary reduction design has the problem of short service life of the middle motor due to unbalanced load when improving the transmission speed ratio by using a planetary reduction structure for transmission.

[0045] In order to solve the above technical problems, as shown in Figure 1 The embodiment of the present application provides a middle motor 100, which belongs to the technical field of power-assisted bicycles and is applied to a power-assisted bicycle with pedals and wheels, and is used for assisting the user to ride.

[0046] As shown in Figures 2 to 5 The middle motor 100 provided by the embodiment includes a driving device 110, a transmission device 120 and an output device 130.

[0047] The driving device 110 has a driving shaft 111, the transmission device 120 includes a fixed ring gear 121, a movable ring gear 122, a sun gear 123 and a plurality of planetary gears 124, the sun gear 123 is connected with the driving shaft 111, the plurality of planetary gears 124 are arranged along the circumferential direction Z of the sun gear 123, and each planetary gear 124 is meshed with the sun gear 123, the fixed ring gear 121 and the movable ring gear 122, respectively. The output device 130 includes an output shaft 131, a first rotating part 132 and a second rotating part 133, the output shaft 131 is connected with the movable ring gear 122, the first rotating part 132 is rotatably arranged on the driving shaft 111, the sun gear 123, the fixed ring gear 121, the movable ring gear 122, the output shaft 131 and the second rotating part 133, respectively, the first rotating part 132, the driving shaft 111, the sun gear 123, the fixed ring gear 121, the movable ring gear 122, the output shaft 131 and the second rotating part 133 are coaxially arranged, the output device 130 further includes a first clutch 134 and a second clutch 135, the first clutch 134 is arranged between the first rotating part 132 and the output shaft 131, the second clutch 135 is arranged between the second rotating part 133 and the output shaft 131, the first rotating part 132 is used for connecting the pedals, and the second rotating part 133 is used for connecting the wheels.

[0048] It should be noted that when the middle motor 100 is used, the driving device 110 drives the sun gear 123 to rotate through the driving shaft 111, the fixed ring gear 121 remains stationary, the sun gear 123 drives the plurality of planet gears 124 to revolve and rotate, the plurality of planet gears 124 drive the movable ring gear 122 to rotate, and the movable ring gear 122 transmits the power provided by the driving device 110 to the output shaft 131. In this process, the transmission device 120 plays a role of speed reduction and torque increase between the driving device 110 and the output device 130. For example, when the user pedals the pedal so that the first rotating part 132 rotates in the first direction to make the power-assisted bicycle move forward, the first clutch 134 is in the engaged state, so that the first rotating part 132 is connected with the output shaft 131 through the first clutch 134; when the power-assisted bicycle moves backward or the user pedals the pedal so that the first rotating part 132 rotates in the second direction opposite to the first direction, the first clutch 134 is in the disengaged state, so that the first rotating part 132 is disconnected from the output shaft 131, to cut off the power transmission between the first rotating part 132 and the output shaft 131. For example, when the driving shaft 111 rotates in the first rotation direction, the second clutch 135 is in the engaged state, so that the second rotating part 133 is connected with the output shaft 131 through the second clutch 135, thereby assisting the power-assisted bicycle; when the driving shaft 111 rotates in the second rotation direction opposite to the first rotation direction, the second clutch 135 is in the disengaged state, so that the second rotating part 133 is disconnected from the output shaft 131, to cut off the power transmission between the second rotating part 133 and the output shaft 131.

[0049] In addition, the coaxial arrangement of the first rotating part 132, the driving shaft 111, the sun gear 123, the fixed ring gear 121, the movable ring gear 122, the output shaft 131 and the second rotating part 133 means that the seven are coaxially arranged, and the axis is parallel to the axial direction X of the middle motor 100 and perpendicular to the radial direction Y of the middle motor 100.

[0050] For example, the number of planet gears 124 can be two, three, four, five, etc., which is not specifically limited here.

[0051] It can be understood that the middle motor 100 provided by the embodiment has the characteristics of large transmission ratio of the transmission device 120 due to the adoption of the planetary reduction structure as the transmission device 120. On this basis, the first rotating part 132 connected with the pedal is respectively rotatably arranged in the driving shaft 111, the sun gear 123, the fixed gear ring 121, the movable gear ring 122, the output shaft 131 and the second rotating part 133 connected with the wheel, and the first rotating part 132, the driving shaft 111, the sun gear 123, the fixed gear ring 121, the movable gear ring 122, the output shaft 131 and the second rotating part 133 are coaxially arranged, so as to reduce the radial Y dimension and the axial X dimension of the middle motor 100, and the structure is more compact, so that the middle motor 100 has both large speed ratio and small size.

[0052] As shown in Figure 2 , Figure 3 and Figure 7 , in one embodiment, the transmission device 120 further comprises a planet carrier 125, and the first rotating part 132 and the driving shaft 111 are respectively rotatably arranged in the planet carrier 125, and the first rotating part 132 and the planet carrier 125 are coaxially arranged, and each planetary gear 124 is rotatably arranged on the planet carrier 125.

[0053] It can be understood that since the first rotating part 132 and the driving shaft 111 are respectively rotatably arranged in the planet carrier 125, and the first rotating part 132 and the planet carrier 125 are coaxially arranged, the radial Y dimension and the axial X dimension of the middle motor 100 are further reduced, which is beneficial to the miniaturization design of the middle motor 100.

[0054] Further, at least one of the sun gear 123, the planet carrier 125 and the fixed gear ring 121 is integrally formed by a plastic material. It can be understood that by the above-mentioned plastic instead of steel, the noise generated during transmission of the transmission device 120 is reduced, and the weight of the transmission device 120 is also reduced, which is beneficial to the lightweight design of the middle motor 100.

[0055] Further, the plastic material is polyether ether ketone (PEEK), which has excellent wear resistance and shock resistance, can maintain a long service life under high load and high speed operation conditions, and can effectively reduce the vibration and noise generated during operation of the transmission device 120. At the same time, polyether ether ketone has smaller weight than metal material, which helps to reduce the weight of the middle motor 100 to realize lightweight.

[0056] Of course, for the above-mentioned embodiment, the plastic material can also be polyamide (PA), polyphenylene sulfide (PPS) and the like, and the type of the plastic material is not specifically limited here.

[0057] As shown in Figures 7 to 10As shown, further, each planetary gear 124 is rotatably connected with the planet carrier 125 through a connecting shaft 126, each planetary gear 124 comprises a connecting portion 1241, a first gear tooth portion 1242 and a second gear tooth portion 1243, the connecting shaft 126 is rotatably arranged in the connecting portion 1241, the first gear tooth portion 1242 and the second gear tooth portion 1243 are coaxially arranged and respectively annularly arranged at the outer circumferential side of the connecting portion 1241, the first gear tooth portion 1242 is respectively engaged with the sun gear 123 and the fixed gear ring 121, and the second gear tooth portion 1243 is engaged with the movable gear ring 122, so that each planetary gear 124 is respectively engaged with the sun gear 123, the fixed gear ring 121 and the movable gear ring 122.

[0058] Exemplarily, the tooth shape of the first gear tooth portion 1242 and / or the tooth shape of the second gear tooth portion 1243 can be selected as straight teeth or helical teeth, which is not specifically limited here.

[0059] It can be understood that each planetary gear 124 comprises the first gear tooth portion 1242 and the second gear tooth portion 1243, i.e., each planetary gear 124 is a double coaxial planetary gear, which can further improve the transmission speed ratio of the in-wheel motor 100 and reduce the volume and weight of the in-wheel motor 100.

[0060] Exemplarily, when the transmission device 120 with the double coaxial planetary gear is selected as a 3K type planetary reduction transmission structure, the transmission speed ratio range that can be achieved is 20-100 (including 20 and 100).

[0061] As shown in Figure 2 , Figure 3 and Figure 9 , still further, the transmission device 120 further comprises a first bearing 127, the outer ring of the first bearing 127 is connected with the connecting portion 1241, and the inner ring of the first bearing 127 is connected with the connecting shaft 126, the first bearing 127 is a cage needle bearing, which has the characteristics of compact structure and small occupied volume, and can further reduce the weight and volume of the in-wheel motor 100, so as to realize the miniaturization and light weight of the whole machine.

[0062] As shown in Figures 7 to 10 , further, the planet carrier 125 comprises a first planet carrier body 1251 and a second planet carrier body 1252 which are coaxially arranged, each planetary gear 124 is rotatably connected between the first planet carrier body 1251 and the second planet carrier body 1252, at least part of the first planet carrier body 1251 is located in the first through hole 1211 of the fixed gear ring 121, and at least part of the second planet carrier body 1252 is located in the second through hole 1221 of the movable gear ring 122.

[0063] It can be understood that, due to the coaxial arrangement of the first planet carrier body 1251 and the second planet carrier body 1252, and the arrangement of at least part of the first planet carrier body 1251 in the first through hole 1211 of the fixed ring gear 121 and at least part of the second planet carrier body 1252 in the second through hole 1221 of the movable ring gear 122, the structure is more compact, thereby reducing the weight and volume of the in-wheel motor 100.

[0064] As shown in Figure 2 and Figure 3 Further, a first floating gap 1321 is provided between the outer periphery of the sun gear 123 and the first rotating member 132; and / or, a second floating gap 1111 is provided between the outer periphery of the planet carrier 125 and the drive shaft 111.

[0065] It can be understood that, by providing the first floating gap 1321, the sun gear 123 can float along the radial direction Y of the in-wheel motor 100, and by providing the second floating gap 1111, the planet carrier 125 can float along the radial direction Y of the in-wheel motor 100. In this way, when the load between the planet gears 124 is unbalanced, automatic positioning can be achieved, thereby balancing the load between the planet gears 124, and further prolonging the service life of the in-wheel motor 100. Especially when the number of planet gears 124 is three and the in-wheel motor 100 is applied to low-speed planetary transmission, the load balancing effect is better.

[0066] As shown in Figure 2 and Figure 3 Further, a spline hole 1112 is provided on the drive shaft 111, and a drum gear 1231 is provided on the outer periphery of the sun gear 123, the drum gear 1231 being arranged in the spline hole 1112 to limit the relative rotation of the sun gear 123 and the drive shaft 111.

[0067] It can be understood that, by the cooperation of the drum gear 1231 and the spline hole 1112, the sun gear 123 and the drive shaft 111 are floatingly connected along the radial direction Y of the in-wheel motor 100. In this way, not only is it convenient for the drive shaft 111 to transmit torque to the sun gear 123, but also when the load between the planet gears 124 is unbalanced, automatic positioning can be achieved, thereby balancing the load between the planet gears 124.

[0068] As shown in Figure 2 , Figure 3 , Figure 6 and Figure 7As shown, further, the transmission 120 further comprises a second bearing 128 and a third bearing 129, the second bearing 128 is supported on one side of the carrier 125 along the axial direction X of the in-wheel motor 100, and the third bearing 129 is supported on the other side of the carrier 125 along the axial direction X of the in-wheel motor 100, both the second bearing 128 and the third bearing 129 are planar thrust bearings, so as to limit the movement of the carrier 125 along the axial direction X of the in-wheel motor 100, thereby reducing the possibility of the carrier 125 moving during transmission, and prolonging the service life of the in-wheel motor 100.

[0069] As shown in Figure 2 , Figure 3 and Figure 11 In one embodiment, the in-wheel motor 100 further comprises a housing 140, the housing 140 comprises a first shell 141, a second shell 142 and a third shell 143, the second shell 142 is connected between the first shell 141 and the second shell 142, the first shell 141, the second shell 142 and the third shell 143 enclose a containing cavity 144, the drive device 110 and the transmission 120 are located in the containing cavity 144, the output shaft 131 is located in the containing cavity 144, at least part of the first rotating part 132 is located in the containing cavity 144, at least part of the second rotating part 133 is located in the containing cavity 144, and the fixed ring gear 121 is fixedly connected with the second shell 142.

[0070] Exemplarily, the fixed connection between the fixed ring gear 121 and the second shell 142 can be a threaded connection, a buckle connection, a magnetic attraction connection, a glue connection, a quick release connection, etc., which is not specifically limited here.

[0071] It can be understood that by dividing the housing 140 into the first shell 141, the second shell 142 and the third shell 143, the three can be independently machined, the machining precision is easier to guarantee, the machining difficulty is reduced and the machining time is shortened. In addition, by accommodating the drive device 110, the transmission 120 and the output device 130 in the housing 140, a protection effect can be achieved, such as dustproof, waterproof and the like, thereby prolonging the service life of the in-wheel motor 100.

[0072] As shown in Figure 2 and Figure 3As shown, further, the driving device 110 comprises a fourth bearing 114 and a fifth bearing 115 which are arranged along the axial direction X of the middle motor 100, the inner ring of the fourth bearing 114 is connected with the driving shaft 111, the outer ring of the fourth bearing 114 is connected with the first housing 141, the inner ring of the fifth bearing 115 is connected with the driving shaft 111, and the outer ring of the fifth bearing 115 is connected with the second housing 142, thereby the driving shaft 111 can be limited to move along the radial direction Y of the middle motor 100, so as to reduce the possibility of the driving shaft 111 moving along the radial direction Y of the middle motor 100 during driving, and prolong the service life of the middle motor 100.

[0073] As shown in Figure 2 and Figure 3 As shown, further, the output device 130 further comprises a sixth bearing 136 and a seventh bearing 137 which are arranged along the axial direction X of the middle motor 100, the inner ring of the sixth bearing 136 is connected with the first rotating member 132, the outer ring of the sixth bearing 136 is connected with the first housing 141, the inner ring of the seventh bearing 137 is connected with the first rotating member 132, and the outer ring of the seventh bearing 137 is connected with the output shaft 131, thereby the first rotating member 132 can be limited to move along the radial direction Y of the middle motor 100, so as to reduce the possibility of the first rotating member 132 moving along the radial direction Y of the middle motor 100 during driving and transmission, and prolong the service life of the middle motor 100.

[0074] As shown in Figures 2 to 4 In one embodiment, the driving device 110 comprises a stator 112 and a rotor 113, the rotor 113 is rotatably arranged in the stator 112 and connected with the driving shaft 111, the rotor 113 can rotate relative to the stator 112 to drive the driving shaft 111 to rotate, so as to transmit power to the transmission device 120 through the driving shaft 111.

[0075] In the second aspect, the embodiments of the present application provide a power-assisted bicycle, which comprises a bicycle body, a bicycle wheel, a pedal, a crank, a sprocket and the middle motor 100 in any of the embodiments of the first aspect, the middle motor 100 and the bicycle wheel are arranged on the bicycle body, the crank is connected between the first rotating member 132 and the pedal, and the sprocket is connected between the second rotating member 133 and the bicycle wheel.

[0076] It should be noted that when using the power-assisted bicycle provided by the embodiments, the driving device 110 drives the sun gear 123 to rotate through the driving shaft 111, the fixed ring gear 121 remains stationary, the sun gear 123 drives the plurality of planet gears 124 to revolve and rotate, the plurality of planet gears 124 drive the movable ring gear 122 to rotate, and the movable ring gear 122 transmits the power provided by the driving device 110 to the output shaft 131, in this process, the transmission device 120 plays a role of speed reduction and torque increase between the driving device 110 and the output device 130.

[0077] Exemplarily, when the user pedals the pedal to rotate the first rotating member 132 in a first direction by means of the crank to make the power-assisted bicycle travel forward, the first clutch 134 is in the engaged state, so that the first rotating member 132 is connected with the output shaft 131 through the first clutch 134; when the power-assisted bicycle travels backward or the user pedals the pedal to rotate the first rotating member 132 in a second direction opposite to the first direction by means of the crank, the first clutch 134 is in the disengaged state, so that the first rotating member 132 is disconnected from the output shaft 131 to cut off the power transmission between the first rotating member 132 and the output shaft 131. Exemplarily, when the drive shaft 111 rotates in a first rotation direction, the second clutch 135 is in the engaged state, so that the second rotating member 133 connected with the chain wheel is connected with the output shaft 131 through the second clutch 135, thereby assisting the power-assisted bicycle; when the drive shaft 111 rotates in a second rotation direction opposite to the first rotation direction, the second clutch 135 is in the disengaged state, so that the second rotating member 133 is disconnected from the output shaft 131 to cut off the power transmission between the second rotating member 133 and the output shaft 131.

[0078] It can be understood that, since the electric power-assisted bicycle provided by the embodiment has the middle motor 100 in any of the embodiments of the first aspect, the electric power-assisted bicycle has all the beneficial effects of the middle motor 100, which will not be described herein.

[0079] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, different embodiments or examples described in the specification and the features of different embodiments or examples can be combined and combined by those skilled in the art without contradiction.

[0080] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A mid-drive motor, characterized in that, For use in power-assisted bicycles with pedals and wheels, the mid-mounted motor includes: The drive unit has a drive shaft; The transmission device includes a fixed gear ring, a movable gear ring, a sun gear and a plurality of planet gears. The sun gear is connected to the drive shaft, and the plurality of planet gears are arranged at circumferential intervals along the sun gear. Each planet gear meshes with the sun gear, the fixed gear ring and the movable gear ring respectively. The output device includes an output shaft, a first rotating member, and a second rotating member. The output shaft is connected to the movable gear ring. The first rotating member is rotatably disposed through the drive shaft, the sun gear, the fixed gear ring, the movable gear ring, the output shaft, and the second rotating member. The first rotating member, the drive shaft, the sun gear, the fixed gear ring, the movable gear ring, the output shaft, and the second rotating member are coaxially arranged. The output device also includes a first clutch and a second clutch. The first clutch is disposed between the first rotating member and the output shaft, and the second clutch is disposed between the second rotating member and the output shaft. The first rotating member is used to connect the pedal, and the second rotating member is used to connect the wheel.

2. The mid-mounted motor according to claim 1, characterized in that, The transmission device further includes a planetary carrier, the first rotating member and the drive shaft are respectively rotatably disposed on the planetary carrier, the first rotating member and the planetary carrier are coaxially disposed, and each planetary gear is rotatably disposed on the planetary carrier.

3. The mid-mounted motor according to claim 2, characterized in that, At least one of the sun gear, the planet carrier, and the fixed gear ring is integrally molded from plastic material.

4. The mid-mounted motor according to claim 3, characterized in that, The plastic material is polyetheretherketone.

5. The mid-mounted motor according to claim 2, characterized in that, Each planetary gear is rotatably connected to the planet carrier via a connecting shaft. Each planetary gear includes a connecting portion, a first gear tooth portion, and a second gear tooth portion. The connecting shaft is rotatably disposed through the connecting portion. The first gear tooth portion and the second gear tooth portion are coaxially disposed and respectively encircle the outer periphery of the connecting portion. The first gear tooth portion meshes with the sun gear and the fixed gear ring, respectively, and the second gear tooth portion meshes with the movable gear ring.

6. The mid-mounted motor according to claim 5, characterized in that, The transmission device further includes a first bearing, the outer ring of which is connected to the connecting part, and the inner ring of which is connected to the connecting shaft. The first bearing is a cage needle roller bearing.

7. The mid-mounted motor according to claim 2, characterized in that, The planetary carrier includes a first planetary carrier body and a second planetary carrier body arranged coaxially. Each planetary gear is rotatably connected between the first planetary carrier body and the second planetary carrier body. At least a portion of the first planetary carrier body is located in the first through hole of the fixed gear ring, and at least a portion of the second planetary carrier body is located in the second through hole of the movable gear ring.

8. The mid-mounted motor according to claim 2, characterized in that, There is a first floating clearance between the sun gear and the outer peripheral side of the first rotating member; and / or, there is a second floating clearance between the planet carrier and the outer peripheral side of the drive shaft.

9. The mid-drive motor according to any one of claims 1 to 8, characterized in that, The mid-mounted motor also includes a housing, which comprises a first housing, a second housing, and a third housing. The second housing is connected between the first housing and the second housing. The first housing, the second housing, and the third housing enclose a receiving cavity. The driving device and the transmission device are located within the receiving cavity. The output shaft is located within the receiving cavity. At least a portion of the first rotating member is located within the receiving cavity. At least a portion of the second rotating member is located within the receiving cavity. The fixed gear ring is fixedly connected to the second housing.

10. A power-assisted bicycle, characterized in that, The vehicle includes a body, wheels, pedals, cranks, sprockets, and a mid-mounted motor as described in any one of claims 1 to 9. The mid-mounted motor and the wheels are respectively disposed on the vehicle body, the cranks are connected between the first rotating member and the pedals, and the sprockets are connected between the second rotating member and the wheels.

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