Middle motor and power-assisted bicycle
By adopting planetary reduction structure and coaxial settings in the mid-motor, the problem of difficulty in taking into account large speed ratio and miniaturization of the mid-motor is solved, and a compact structural design and efficient transmission performance are achieved.
Patent Information
- Application Number
- CN202411999734.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2025-03-11
AI Technical Summary
It is difficult for the mid-mounted motor to take into account the problems of large speed ratio and miniaturization.
The planetary deceleration structure is used as the transmission device. Through the combination of the sun gear, the planetary wheel, the fixed ring gear and the movable ring gear, a large transmission speed ratio is achieved, and the radial and axial dimensions of the central motor are reduced through coaxial settings and floating clearance designs.
The large speed ratio and miniaturization of the mid-mounted motor are achieved, and the structure is more compact, taking into account both performance and volume.
Smart Images
Figure CN119590546A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of power-assisted bicycles, and in particular to a mid-mounted motor and a power-assisted bicycle. Background Art
[0002] The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the present disclosure, and should not be regarded as acknowledging or suggesting in any form that the information constitutes the prior art known to those skilled in the art.
[0003] A power-assisted bicycle is a new type of transportation that can realize the integration of human riding and motor assistance. The motor installed in the middle of the body of the power-assisted bicycle is called a mid-mounted motor. The mid-mounted motor is connected to the wheels of the power-assisted bicycle to provide assistance. At the same time, pedals of the power-assisted bicycle are installed on both sides of the mid-mounted motor. When the mid-mounted motor has no power supply, the user can achieve human riding by pedaling. In the related art, the mid-mounted motor used in the power-assisted bicycle adopts a three-stage parallel transmission structure, which has the problem of difficulty in taking into account both a large speed ratio and miniaturization. Summary of the invention
[0004] In view of this, the purpose of the present application is to provide a mid-mounted motor and a power-assisted bicycle, aiming to solve the technical problem in the related art that the mid-mounted motor is difficult to achieve both high speed ratio and miniaturization.
[0005] To achieve the above objectives, the technical solutions adopted in this application are as follows:
[0006] In a first aspect, an embodiment of the present application provides a mid-mounted motor, which is applied to a power-assisted bicycle having pedals and wheels, and the mid-mounted motor includes:
[0007] A drive device having a drive shaft;
[0008] A transmission device, comprising a fixed gear ring, a movable gear ring, a sun gear and a plurality of planetary gears, wherein the sun gear is connected to the drive shaft, the plurality of planetary gears are arranged at intervals along the circumference of the sun gear, and each of the planetary gears is respectively meshed with the sun gear, the fixed gear ring and the movable gear ring;
[0009] The output device comprises an output shaft, a first rotating member and a second rotating member, the output shaft is connected to the movable ring gear, the first rotating member 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, 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, the output device also 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 to connect the pedal, and the second rotating member is used to connect the wheel.
[0010] In one of the embodiments of the first aspect, the transmission device also includes a planetary carrier, the first rotating member and the drive shaft are respectively rotatably arranged in the planetary carrier, the first rotating member and the planetary carrier are coaxially arranged, and each of the planetary gears is rotatably arranged on the planetary carrier.
[0011] In one embodiment of the first aspect, at least one of the sun gear, the planet carrier and the fixed ring gear is made of plastic material and is integrally molded.
[0012] In one embodiment of the first aspect, the plastic material is polyetheretherketone.
[0013] In one embodiment of the first aspect, each of the planetary gears is rotatably connected to the planetary carrier via a connecting shaft, and each of the planetary gears includes a connecting portion, a first gear tooth portion, and a second gear tooth portion. The connecting shaft is rotatably inserted into the connecting portion, and the first gear tooth portion and the second gear tooth portion are coaxially arranged and respectively annularly arranged on the outer peripheral side of the connecting portion. The first gear tooth portion is respectively meshed with the sun gear and the fixed gear ring, and the second gear tooth portion is meshed with the movable gear ring.
[0014] In one embodiment of the first aspect, the transmission device further includes a first bearing, an outer ring of the first bearing is connected to the connecting portion, an inner ring of the first bearing is connected to the connecting shaft, and the first bearing is a retainer needle roller bearing.
[0015] In one embodiment of the first aspect, the planet carrier includes a first planet carrier body and a second planet carrier body coaxially arranged, each of the planetary gears is rotatably connected between the first planet carrier body and the second planet carrier body, at least a portion of the first planet carrier body is located in the first through hole of the fixed gear ring, and at least a portion of the second planet carrier body is located in the second through hole of the movable gear ring.
[0016] In one embodiment of the first aspect, a first floating gap is provided between the sun gear and the outer circumference of the first rotating member; and / or a second floating gap is provided between the planet carrier and the outer circumference of the drive shaft.
[0017] In one of the embodiments of the first aspect, the central motor also includes a shell, the shell includes 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 are combined to form an accommodating cavity, the driving device and the transmission device are located in the accommodating cavity, the output shaft is located in the accommodating cavity, at least a portion of the first rotating member is located in the accommodating cavity, at least a portion of the second rotating member is located in the accommodating cavity, and the fixed ring gear is fixedly connected to the second shell.
[0018] In a second aspect, an embodiment of the present application provides a power-assisted bicycle, comprising a body, wheels, pedals, cranks, sprockets and the mid-mounted motor described in any embodiment of the first aspect, wherein the mid-mounted motor and the wheel are respectively arranged on the body, the crank is connected between the first rotating member and the pedal, and the sprocket is connected between the second rotating member and the wheel.
[0019] The beneficial effects of this application are as follows:
[0020] The mid-mounted motor provided in the present application adopts a planetary reduction structure as a transmission device, so that the transmission device has the characteristic of a large transmission speed ratio. On this basis, a first rotating member connected to 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 to the 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, which reduces the radial size and axial size of the mid-mounted motor and makes the structure more compact, thereby allowing the mid-mounted motor to take into account both a large speed ratio and miniaturization.
[0021] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and understandable, preferred embodiments are specifically listed below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1A schematic diagram of the structure of a central motor in one embodiment of the present application is shown from one perspective;
[0024] Figure 2 Another perspective structural diagram of a central motor in one embodiment of the present application is shown;
[0025] Figure 3 Shows Figure 2 Schematic diagram of the cross-sectional structure at AA in the middle;
[0026] Figure 4 A schematic diagram of the structure from one perspective of a central motor hidden behind a housing in one embodiment of the present application is shown;
[0027] Figure 5 Shows Figure 4 Schematic diagram of the decomposition structure;
[0028] Figure 6 A schematic diagram of the exploded structure of a transmission device in one embodiment of the present application is shown;
[0029] Figure 7 A schematic diagram of the exploded structure of a transmission device in one embodiment of the present application from another perspective is shown;
[0030] Figure 8 A schematic diagram of the structure of a transmission device after hiding the movable gear ring in one embodiment of the present application from one perspective is shown;
[0031] Fig. 9 A schematic structural diagram from another perspective of a transmission device in one embodiment of the present application after the movable gear ring is hidden;
[0032] Fig.10 A schematic diagram of the structure of the transmission device in one embodiment of the present application after the movable gear ring is hidden is shown from another perspective;
[0033] Fig.11 A schematic diagram of the exploded structure of a housing in one embodiment of the present application is shown.
[0034] Description of main component symbols:
[0035] 100- mid-mounted motor; 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 gear ring; 1211- first through hole; 122- movable gear ring; 1221- second through hole; 123- sun gear; 1231- drum-shaped tooth; 124- planetary gear; 1241- connecting part; 1242- first gear tooth part; 1243- second gear tooth part; 125- planetary 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 shell; 142-second shell; 143-third shell; 144-accommodating chamber; X-axial; Y-radial; Z-circumferential. DETAILED DESCRIPTION
[0036] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0037] In the description of the present application, terms such as "center", "longitudinal", "lateral", "length", "width", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.
[0038] In addition, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.
[0039] In the description of this application, the terms "first", "second", etc. are used to distinguish different objects and cannot be understood as indicating or implying a specific order or a primary and secondary relationship, or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the feature. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.
[0040] In the description of this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
[0041] In the description of this application, the term "and / or" indicates that there may be three relationships. For example, A and / or B may indicate that A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " generally indicates that the objects associated with each other are in an "or" relationship.
[0042] In the description of this application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "perpendicular" also includes not only the absolutely perpendicular situation, but also the roughly perpendicular situation conventionally recognized in engineering. For example, if the angle between two directions is 80° to 90°, the two directions can be considered perpendicular; if the angle between two directions is 0° to 10°, the two directions can be considered parallel.
[0043] Power-assisted bicycles are a new type of transportation that can realize the integration of human riding and motor assistance. The motor installed in the middle of the power-assisted bicycle is called a mid-mounted motor. The mid-mounted motor is connected to the wheels of the power-assisted bicycle to provide assistance. At the same time, pedals of the power-assisted bicycle are installed on both sides of the mid-mounted motor. When the mid-mounted motor has no power supply, the user can achieve human riding by pedaling.
[0044] In the related art, the central motor used in the power-assisted bicycle adopts a three-stage parallel transmission structure, which has the problem of difficulty in taking into account a large speed ratio, miniaturization and light weight. In addition, the inventors adopted a planetary reduction structure for transmission, which increased the transmission speed ratio and further found that the planetary reduction design had a problem of unbalanced load, which led to a short life of the central motor.
[0045] In order to solve the above technical problems, Figure 1 As shown, in the first aspect, an embodiment of the present application provides a mid-mounted motor 100, which relates to the technical field of power-assisted bicycles and is applied to power-assisted bicycles with pedals and wheels to assist users in riding.
[0046] Combination Figures 2 to 5 As shown, the mid-mounted motor 100 provided in this embodiment includes: a driving device 110 , a transmission device 120 and an output device 130 .
[0047] Among them, the driving device 110 has a driving shaft 111, and 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 to the driving shaft 111, and the plurality of planetary gears 124 are arranged at intervals along the circumferential direction Z of the sun gear 123. Each planetary gear 124 is respectively meshed with the sun gear 123, the fixed ring gear 121 and the movable ring gear 122. The output device 130 includes an output shaft 131, a first rotating member 132 and a second rotating member 133. The output shaft 131 is connected to the movable ring gear 122. The first rotating member 132 is rotatably arranged on the drive shaft 111, the sun gear 123, the fixed ring gear 121, the movable ring gear 122, the output shaft 131 and the second rotating member 133 respectively. The first rotating member 132, the drive shaft 111, the sun gear 123, the fixed ring gear 121, the movable ring gear 122, the output shaft 131 and the second rotating member 133 are coaxially arranged. The output device 130 also includes a first clutch 134 and a second clutch 135. The first clutch 134 is arranged between the first rotating member 132 and the output shaft 131, and the second clutch 135 is arranged between the second rotating member 133 and the output shaft 131. The first rotating member 132 is used to connect the pedal, and the second rotating member 133 is used to connect the wheel.
[0048] It should be noted that when the mid-mounted motor 100 provided in this embodiment is used, the drive device 110 drives the sun gear 123 to rotate through the drive shaft 111, and the fixed ring gear 121 remains stationary. The sun gear 123 drives the multiple planetary gears 124 to revolve and rotate, and the multiple planetary gears 124 drive the movable ring gear 122 to rotate. The movable ring gear 122 transmits the power provided by the drive device 110 to the output shaft 131. In this process, the transmission device 120 plays a role of reducing speed and increasing torque between the drive device 110 and the output device 130. Exemplarily, when the user pedals to rotate the first rotating member 132 in the first direction so that the power-assisted bicycle moves forward, the first clutch 134 is in an engaged state, so that the first rotating member 132 is connected to the output shaft 131 through the first clutch 134; when the power-assisted bicycle moves backward or the user pedals to rotate the first rotating member 132 in the second direction opposite to the first direction, the first clutch 134 is in a disengaged state, so that the first rotating member 132 is separated 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 the first rotation direction, the second clutch 135 is in an engaged state, so that the second rotating member 133 is connected to the output shaft 131 through the second clutch 135, thereby providing power for the power-assisted bicycle; when the drive shaft 111 rotates in the second rotation direction opposite to the first rotation direction, the second clutch 135 is in a disengaged state, so that the second rotating member 133 is separated from the output shaft 131 to cut off the power transmission between the second rotating member 133 and the output shaft 131.
[0049] In addition, the coaxial arrangement of the above-mentioned first rotating member 132, drive shaft 111, sun gear 123, fixed ring gear 121, movable ring gear 122, output shaft 131 and second rotating member 133 refers to the coaxial arrangement of the seven, which is parallel to the axial direction X of the mid-mounted motor 100 and perpendicular to the radial direction Y of the mid-mounted motor 100.
[0050] Exemplarily, the number of the planetary gears 124 may be two, three, four, five, etc., and no specific limitation is made herein.
[0051] It can be understood that the mid-mounted motor 100 provided in this embodiment adopts a planetary reduction structure as the transmission device 120, so that the transmission device 120 has the characteristic of a large transmission speed ratio. On this basis, the first rotating member 132 connected to the pedal is rotatably arranged on the drive shaft 111, the sun gear 123, the fixed ring gear 121, the movable ring gear 122, the output shaft 131 and the second rotating member 133 connected to the wheel, and the first rotating member 132, the drive shaft 111, the sun gear 123, the fixed ring gear 121, the movable ring gear 122, the output shaft 131 and the second rotating member 133 are coaxially arranged, which reduces the radial Y dimension and axial X dimension of the mid-mounted motor 100, and the structure is more compact, thereby allowing the mid-mounted motor 100 to take into account both a large speed ratio and miniaturization.
[0052] like Figure 2 , Figure 3 and Figure 7 As shown, in one embodiment, the transmission device 120 also includes a planetary carrier 125, the first rotating member 132 and the drive shaft 111 are respectively rotatably disposed in the planetary carrier 125, the first rotating member 132 and the planetary carrier 125 are coaxially disposed, and each planetary gear 124 is rotatably disposed on the planetary carrier 125.
[0053] It can be understood that since the first rotating member 132 and the driving shaft 111 are respectively rotatably arranged in the planetary carrier 125, and the first rotating member 132 and the planetary carrier 125 are coaxially arranged, the radial Y dimension and axial X dimension of the center motor 100 are further reduced, which is conducive to the miniaturized design of the center motor 100.
[0054] Furthermore, at least one of the sun gear 123, the planet carrier 125 and the fixed gear ring 121 is made of plastic material in one piece. It can be understood that by replacing steel with plastic, the noise generated by the transmission device 120 during transmission is reduced, and the weight of the transmission device 120 is also reduced, which is conducive to the lightweight design of the mid-mounted motor 100.
[0055] Furthermore, the plastic material is polyetheretherketone (PEEK), which has excellent wear resistance and shock absorption, can maintain a long service life under high load and high-speed operation conditions, and can effectively reduce the vibration and noise generated during the operation of the transmission device 120. At the same time, polyetheretherketone has a smaller weight than metal materials, which helps to reduce the weight of the mid-mounted motor 100 to achieve lightweight.
[0056] Of course, for the above embodiments, the plastic material may also be polyamide (PA), polyphenylene sulfide (PPS), etc., and no specific limitation is imposed on the type of plastic material.
[0057] like Figures 7 to 10As shown, further, each planetary gear 124 is rotatably connected to the planetary carrier 125 via a connecting shaft 126, and each planetary gear 124 includes 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 on the outer peripheral side of the connecting portion 1241, the first gear tooth portion 1242 is respectively meshed with the sun gear 123 and the fixed ring gear 121, and the second gear tooth portion 1243 is meshed with the movable ring gear 122, so that each planetary gear 124 is respectively meshed with the sun gear 123, the fixed ring gear 121 and the movable ring gear 122.
[0058] For example, the tooth shape of the first gear tooth portion 1242 and / or the tooth shape of the second gear tooth portion 1243 may be straight teeth or helical teeth, and no specific limitation is made here.
[0059] It can be understood that each planetary gear 124 includes a first gear tooth portion 1242 and a second gear tooth portion 1243, that is, each planetary gear 124 is a double coaxial planetary gear, which can further improve the transmission speed ratio of the mid-mounted motor 100 and reduce the volume and weight of the mid-mounted motor 100.
[0060] For example, when the transmission device 120 having double coaxial planetary gears selects a 3K type planetary reduction transmission structure, the achievable transmission speed ratio range is 20 to 100 (including 20 and 100).
[0061] like Figure 2 , Figure 3 and Fig. 9 As shown, further, the transmission device 120 also includes a first bearing 127, the outer ring of the first bearing 127 is connected to the connecting portion 1241, the inner ring of the first bearing 127 is connected to the connecting shaft 126, and the first bearing 127 is a retainer needle roller bearing. The retainer needle roller bearing has a compact structure and occupies a small volume, which can further reduce the weight and volume of the central motor 100 and realize the miniaturization and lightweight of the entire machine.
[0062] like Figures 7 to 10 As shown, further, the planet carrier 125 includes 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 a portion of the first planet carrier body 1251 is located in the first through hole 1211 of the fixed ring gear 121, and at least a portion of the second planet carrier body 1252 is located in the second through hole 1221 of the movable ring gear 122.
[0063] It can be understood that since the first planetary carrier body 1251 and the second planetary carrier body 1252 are coaxially arranged, and at least a portion of the first planetary carrier body 1251 is located in the first through hole 1211 of the fixed ring gear 121, and at least a portion of the second planetary carrier body 1252 is located in the second through hole 1221 of the movable ring gear 122, this can make the structure more compact, thereby reducing the weight and volume of the mid-mounted motor 100.
[0064] like Figure 2 and Figure 3 As shown, further, a first floating gap 1321 is provided between the sun gear 123 and the outer circumference of the first rotating member 132 ; and / or a second floating gap 1111 is provided between the planet carrier 125 and the outer circumference of the driving shaft 111 .
[0065] It can be understood that, by setting the first floating gap 1321, the sun gear 123 can float along the radial direction Y of the mid-mounted motor 100, and by setting the second floating gap 1111, the planet carrier 125 can float along the radial direction Y of the mid-mounted motor 100. In this way, when there is an unbalanced load between the planetary gears 124, the automatic adjustment can be achieved, so that the load between the planetary gears 124 is balanced, thereby extending the service life of the mid-mounted motor 100. In particular, when there are three planetary gears 124 and they are applied to medium and low speed planetary transmissions, the load balancing effect is better.
[0066] like Figure 2 and Figure 3 As shown, further, a spline hole 1112 is provided on the driving shaft 111 , and a drum-shaped tooth 1231 is provided on the outer peripheral side of the sun gear 123 . The drum-shaped tooth 1231 penetrates the spline hole 1112 to limit the relative rotation between the sun gear 123 and the driving shaft 111 .
[0067] It can be understood that, through the cooperation between the drum-shaped teeth 1231 and the spline holes 1112, the sun gear 123 and the drive shaft 111 are connected in a floating manner along the radial direction Y of the central motor 100. In this way, it is not only convenient for the drive shaft 111 to transmit torque to the sun gear 123, but also when there is an unbalanced load between the planetary gears 124, the automatic adjustment function can be achieved, so that the load between the planetary gears 124 is balanced.
[0068] like Figure 2 , Figure 3 , Figure 6 and Figure 7As shown, further, the transmission device 120 also includes a second bearing 128 and a third bearing 129. The second bearing 128 is supported on one side of the planetary carrier 125 along the axial direction X of the mid-mounted motor 100, and the third bearing 129 is supported on the other side of the planetary carrier 125 along the axial direction X of the mid-mounted motor 100. The second bearing 128 and the third bearing 129 are both planar thrust bearings to limit the movement of the planetary carrier 125 along the axial direction X of the mid-mounted motor 100, thereby reducing the possibility of movement of the planetary carrier 125 during transmission and extending the service life of the mid-mounted motor 100.
[0069] like Figure 2 , Figure 3 and Fig.11 As shown, in one embodiment, the mid-mounted motor 100 also includes a housing 140, the housing 140 includes 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 receiving cavity 144, the driving device 110 and the transmission device 120 are located in the receiving cavity 144, the output shaft 131 is located in the receiving cavity 144, at least a portion of the first rotating member 132 is located in the receiving cavity 144, at least a portion of the second rotating member 133 is located in the receiving cavity 144, and the fixed ring gear 121 is fixedly connected to the second shell 142.
[0070] Exemplarily, the fixed connection between the fixed gear ring 121 and the second shell 142 can be a threaded connection, a snap connection, a magnetic connection, an adhesive connection, a quick-release connection, etc., and no specific limitation is made here.
[0071] It is understandable that by dividing the housing 140 into the first housing 141, the second housing 142 and the third housing 143, the three can be processed separately and independently, the processing accuracy is easier to ensure, the processing difficulty is reduced and the processing time is shortened. In addition, the housing 140 is used to accommodate the driving device 110, the transmission device 120 and the output device 130, which can play a protective role, such as dustproof and waterproof, thereby extending the service life of the central motor 100.
[0072] like Figure 2 and Figure 3As shown, further, the driving device 110 includes a fourth bearing 114 and a fifth bearing 115 which are spaced apart along the axial direction X of the mid-mounted motor 100, the inner ring of the fourth bearing 114 is connected to the driving shaft 111, the outer ring of the fourth bearing 114 is connected to the first shell 141, the inner ring of the fifth bearing 115 is connected to the driving shaft 111, and the outer ring of the fifth bearing 115 is connected to the second shell 142, thereby limiting the movement of the driving shaft 111 along the radial direction Y of the mid-mounted motor 100, thereby reducing the possibility of the driving shaft 111 moving along the radial direction Y of the mid-mounted motor 100 during the driving process, and extending the service life of the mid-mounted motor 100.
[0073] like Figure 2 and Figure 3 As shown, further, the output device 130 also includes a sixth bearing 136 and a seventh bearing 137 spaced apart along the axial direction X of the central motor 100, the inner ring of the sixth bearing 136 is connected to the first rotating member 132, the outer ring of the sixth bearing 136 is connected to the first housing 141, the inner ring of the seventh bearing 137 is connected to the first rotating member 132, and the outer ring of the seventh bearing 137 is connected to the output shaft 131, thereby limiting the movement of the first rotating member 132 along the radial direction Y of the central motor 100, thereby reducing the possibility of the first rotating member 132 moving along the radial direction Y of the central motor 100 during driving and transmission, and extending the service life of the central motor 100.
[0074] like Figures 2 to 4 As shown, in one embodiment, the driving device 110 includes a stator 112 and a rotor 113. The rotor 113 is rotatably disposed in the stator 112 and is connected to the driving shaft 111. The rotor 113 can rotate relative to the stator 112 to drive the driving shaft 111 to rotate, thereby transmitting power to the transmission device 120 through the driving shaft 111.
[0075] In the second aspect, an embodiment of the present application provides a power-assisted bicycle, comprising a body, wheels, pedals, cranks, sprockets and a mid-mounted motor 100 in any embodiment of the first aspect, wherein the mid-mounted motor 100 and the wheels are respectively arranged on the body, the crank is connected between the first rotating member 132 and the pedals, and the sprocket is connected between the second rotating member 133 and the wheels.
[0076] It should be noted that when using the power-assisted bicycle provided by this embodiment, the driving device 110 drives the sun gear 123 to rotate through the driving shaft 111, and the fixed ring gear 121 remains stationary. The sun gear 123 drives the multiple planetary gears 124 to revolve and rotate, and the multiple planetary gears 124 drive the movable ring gear 122 to rotate. 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 reducing speed and increasing torque between the driving device 110 and the output device 130.
[0077] Illustratively, when the user pedals to rotate the first rotating member 132 in a first direction with the help of the crank so that the power-assisted bicycle moves forward, the first clutch 134 is in an engaged state, so that the first rotating member 132 is connected to the output shaft 131 through the first clutch 134; when the power-assisted bicycle moves backward or the user pedals to rotate the first rotating member 132 in a second direction opposite to the first direction with the help of the crank, the first clutch 134 is in a disengaged state, so that the first rotating member 132 is disengaged from the output shaft 131, thereby cutting off the power transmission between the first rotating member 132 and the output shaft 131. Illustratively, when the drive shaft 111 rotates along a first rotation direction, the second clutch 135 is in an engaged state, so that the second rotating member 133 connected to the sprocket is connected to the output shaft 131 through the second clutch 135, thereby providing power to the power-assisted bicycle; when the drive shaft 111 rotates along a second rotation direction opposite to the first rotation direction, the second clutch 135 is in a disengaged state, so that the second rotating member 133 is disengaged 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-assisted bicycle provided in this embodiment has the mid-mounted motor 100 in any embodiment of the first aspect mentioned above, it has all the beneficial effects of the mid-mounted motor 100, which will not be described in detail here.
[0079] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, 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 limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.
Claims
1. A mid-mounted motor, characterized in that: Applied to a power-assisted bicycle with pedals and wheels, the mid-mounted motor comprises: A drive device having a drive shaft; A transmission device, comprising a fixed gear ring, a movable gear ring, a sun gear and a plurality of planetary gears, wherein the sun gear is connected to the drive shaft, the plurality of planetary gears are arranged at intervals along the circumference of the sun gear, and each of the planetary gears is respectively meshed with the sun gear, the fixed gear ring and the movable gear ring; The output device comprises an output shaft, a first rotating member and a second rotating member, the output shaft is connected to the movable ring gear, the first rotating member 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, 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, the output device also 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 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 also includes a planetary carrier, the first rotating member and the driving shaft are respectively rotatably arranged on the planetary carrier, the first rotating member and the planetary carrier are coaxially arranged, and each of the planetary gears is rotatably arranged 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 made of plastic material and integrally formed.
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 of the planetary gears is rotatably connected to the planetary carrier via a connecting shaft, and each of the planetary gears includes a connecting portion, a first gear tooth portion, and a second gear tooth portion. The connecting shaft is rotatably inserted into the connecting portion, and the first gear tooth portion and the second gear tooth portion are coaxially arranged and respectively annularly arranged on the outer peripheral side of the connecting portion. The first gear tooth portion is respectively meshed with the sun gear and the fixed gear ring, and the second gear tooth portion is meshed with the movable gear ring.
6. The mid-mounted motor according to claim 5, characterized in that: The transmission device further comprises a first bearing, an outer ring of the first bearing is connected to the connecting portion, an inner ring of the first bearing is connected to the connecting shaft, and the first bearing is a retainer needle roller bearing.
7. The mid-mounted motor according to claim 2, characterized in that: The planet carrier includes a first planet carrier body and a second planet carrier body which are coaxially arranged, each of the planetary gears is rotatably connected between the first planet carrier body and the second planet carrier body, at least a portion of the first planet carrier body is located in the first through hole of the fixed gear ring, and at least a portion of the second planet 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: A first floating gap is provided between the sun gear and the outer circumference of the first rotating member; and / or a second floating gap is provided between the planet carrier and the outer circumference of the drive shaft.
9. The mid-mounted motor according to any one of claims 1 to 8, characterized in that: The mid-mounted motor also includes a shell, which includes 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 are combined to form an accommodating cavity, the driving device and the transmission device are located in the accommodating cavity, the output shaft is located in the accommodating cavity, at least a portion of the first rotating member is located in the accommodating cavity, at least a portion of the second rotating member is located in the accommodating cavity, and the fixed ring gear is fixedly connected to the second shell.
10. A power-assisted bicycle, characterized in that: It includes a body, wheels, pedals, cranks, sprockets and a mid-mounted motor as described in any one of claims 1 to 9, wherein the mid-mounted motor and the wheels are respectively arranged on the body, the crank is connected between the first rotating member and the pedals, and the sprocket is connected between the second rotating member and the wheel.