A housing, a central shaft transmission and a central motor

Abstract

The utility model belongs to the technical field of transmission, especially relates to a shell, central shaft transmission and centrally -placed motor. The shell of the utility model includes shell main part, is provided with cooperation portion in shell main part inside, is separated into first accommodating cavity and second accommodating cavity through cooperation portion, and the third accommodating cavity formed in cooperation portion inside, the gear shifting mechanism of central shaft transmission is assembled to first accommodating cavity through first direction, the transmission mechanism of central shaft transmission is assembled to second accommodating cavity and third accommodating cavity through second direction, and first direction is opposite with second direction. Only need to process cooperation portion in shell main part, can install gear shifting mechanism and transmission mechanism through two directions respectively, be favorable to improving assembly efficiency. Cooperation portion simple structure, easy to process, low in manufacturing cost. Cooperation portion will bear the rotating control piece of gear shifting mechanism, can improve assembly accuracy and assembly reliability.

Description

Technical Field

[0001] This utility model belongs to the field of transmission technology, and specifically relates to a housing, a central shaft transmission, and a centrally mounted motor. Background Technology

[0002] The internal components of a center-shaft gearbox are installed within a housing. Center-shaft gearboxes have a complex structure and numerous parts, requiring high assembly precision, efficiency, and reliability. Existing center-shaft gearbox housings are insufficient to meet these requirements. Therefore, existing technologies need improvement and development. Utility Model Content

[0003] The purpose of this application is to provide a housing, a central shaft gearbox, and a centrally mounted motor that can improve assembly efficiency.

[0004] To solve the above-mentioned technical problems, this application provides a housing, including a housing body, a mating part provided on the inner side of the housing body, which divides the housing body into a first receiving cavity and a second receiving cavity, and a third receiving cavity formed on the inner side of the mating part. A shifting mechanism of a central shaft transmission is assembled to the first receiving cavity in a first direction, and a transmission mechanism of the central shaft transmission is assembled to the second receiving cavity and the third receiving cavity in a second direction, wherein the first direction is opposite to the second direction.

[0005] Furthermore, the cross-sectional shape of the mating part is stepped.

[0006] Furthermore, the mating part includes a first end face, a third circumferential face, a second end face, a fourth circumferential face, and a third end face connected in sequence. The outer shell body is provided with a first circumferential face. The first circumferential face, the first end face, the third circumferential face, the second end face, the fourth circumferential face, and the third end face form the first receiving cavity.

[0007] Furthermore, the shifting mechanism includes at least two pawls, at least two locking members, an elastic member, a bracket, and a rotation control member. The pawls are rotatably mounted on the bracket. One end of the elastic member abuts against the bracket, and the other end of the elastic member abuts against the pawl. The outer circumferential surface of the rotation control member is provided with a control groove. The pawl is disposed between the locking member and the rotation control member. The locking member is fixedly connected to the sun gear of the transmission mechanism. When the rotation control member rotates to a specific angle, one end of the pawl falls into the control groove, locking the pawl with the locking member to change the transmission ratio.

[0008] The rotation control component and the bracket are assembled in the first receiving cavity.

[0009] Furthermore, the mating part includes a fifth end face, a sixth circumferential face, a fourth end face, and a fifth circumferential face connected in sequence, the outer shell body is provided with a second circumferential face, the fifth end face and the second circumferential face form a second receiving cavity, and the sixth circumferential face, the fourth end face, and the fifth circumferential face form a third receiving cavity.

[0010] Furthermore, the transmission mechanism includes a planet carrier, planetary gears, a sun gear, and a ring gear. The planetary gears are rotatably supported on the planet carrier. The planetary gears externally mesh with the sun gear, and the ring gear internally meshes with the planetary gears.

[0011] The planet carrier, the planetary gear, the sun gear, and the ring gear are assembled in the second receiving cavity and the third receiving cavity.

[0012] Furthermore, the sum of the tip circle radius of the planetary gear and the center distance of the transmission mechanism is less than the radius of the third receiving cavity.

[0013] This application also provides a central shaft transmission, including the aforementioned housing, and further comprising:

[0014] A center axle, which is rotatably supported on the frame, and from which torque is input;

[0015] A transmission mechanism, comprising a planetary carrier connected to the central shaft, through which torque is transmitted, and having at least two transmission ratios;

[0016] A shifting mechanism, linked to the transmission mechanism, is used to change the transmission ratio of the transmission mechanism;

[0017] A drive unit is connected to the gear shifting mechanism;

[0018] The output component is connected to the transmission mechanism to output torque;

[0019] The transmission mechanism, the shifting mechanism, and the drive device are installed inside the housing.

[0020] This application also provides a mid-drive motor, characterized in that it includes the above-mentioned mid-shaft gearbox and also includes an assist motor, the assist motor being connected to the mid-shaft or the transmission mechanism.

[0021] Furthermore, the auxiliary motor is arranged with its axis parallel to the central shaft.

[0022] Furthermore, the power assist motor is connected to the central shaft or the transmission mechanism via any one of chain drive, belt drive, or gear drive.

[0023] As can be seen from the above, the housing, central shaft gearbox, and centrally mounted motor of this application include a housing body. Only a mating part needs to be machined into the housing body to allow the shifting mechanism and transmission mechanism to be installed in two directions respectively, which improves assembly efficiency. The mating part has a simple structure, is easy to machine, and has low manufacturing cost. The mating part supports the rotation control components of the shifting mechanism, improving assembly accuracy and reliability.

[0024] Other features and advantages of this application will be set forth in the following description and will be apparent in part from the description or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings. Attached Figure Description

[0025] Figure 1 This is a 3D view of the central shaft transmission.

[0026] Figure 2 This is a three-dimensional view of the main body of the outer shell.

[0027] Figure 3 This is a three-dimensional view of the main body of the outer shell from another angle.

[0028] Figure 4 This is a cross-sectional view of the main body of the outer casing.

[0029] Figure 5 for Figure 4 A magnified view of a portion of point A.

[0030] Figure 6 This is a cross-sectional view of the central shaft transmission.

[0031] Figure 7 for Figure 6 A magnified view of a portion of point B.

[0032] Figure 8 A perspective view of the central shaft gearbox (with the housing, output components, and crankshaft hidden).

[0033] Figure 9 This is a three-dimensional view of the central shaft gearbox (with the housing, output components, and crankshaft hidden).

[0034] Figure 10 This is a simplified structural diagram of the central shaft transmission.

[0035] Figure 11 This is an exploded view of the gear shifting mechanism.

[0036] Figure 12 This is a cross-sectional view of the gear shifting process of the gear shifting mechanism.

[0037] Figure 13 A 3D view of the locking components, bushings, and sun gear before assembly.

[0038] Figure 14 A 3D view of the locking components, bushings, and sun gear after assembly.

[0039] Figure 15 This is a 3D view of the gear shifting mechanism in the first gear position.

[0040] Figure 16 This is a 3D view of the shift mechanism in the second gear position.

[0041] Figure 17 This is a 3D view of the gear shift mechanism in the third gear position.

[0042] Figure 18 This is a 3D view of the gear shift mechanism in the fourth gear position.

[0043] Figure 19 This is a power transmission path diagram for the first gear of the central shaft transmission.

[0044] Figure 20 This is a diagram showing the power transmission path for the second gear of the central shaft transmission.

[0045] Figure 21 This is a power transmission path diagram for the third gear of the central shaft transmission.

[0046] Figure 22 This is a power transmission path diagram for the fourth gear of the central shaft transmission.

[0047] Figure 23 This is a 3D view of a mid-drive motor (with the housing, output components, and crank hidden).

[0048] Figure 24 This is a 3D view of the mid-drive motor (without housing, output components, or crank).

[0049] Figure 25 This is a simplified structural diagram of a mid-drive motor.

[0050] Explanation of reference numerals in the attached figures:

[0051] 1-Outer shell, 11-Outer shell body, 111-First receiving cavity, 1111-First circumferential surface, 112-Second receiving cavity, 1121-Second circumferential surface, 113-Mating part, 1131-First end face, 1132-Third circumferential surface, 1133-Second end face, 1134-Fourth circumferential surface, 1135-Third end face, 1136-Fifth circumferential surface, 1137-Fourth end face, 1138-Sixth circumferential surface, 1139-Fifth end face, 114-Third receiving cavity, 12-First end cap, 13-Second end cap

[0052] 2-Central axis,

[0053] 3-Input component, 31-Left crank, 32-Right crank

[0054] 4-Output components,

[0055] 5-Transmission mechanism, 51-Planet carrier, 511-Planet carrier body, 5111-Groove, 512-Connecting arm, 513-Third hole, 52-Sun gear, 521-First sun gear, 522-Second sun gear, 523-Third sun gear, 53-Planet gear, 531-First planet gear, 532-Second planet gear, 533-Third planet gear, 54-Ring gear, 55-First clutch assembly, 56-Second clutch assembly

[0056] 6-Shifting mechanism; 61-Pawl; 611-First pawl; 612-Second pawl; 613-Third pawl; 61A-Locking part; 61B-Control part; 61C-Rotating shaft part; 62-Rotation control component; 621-Control groove; 622-Gear tooth; 63-Locking component; 631-First locking component; 632-Second locking component; 633-Third locking component; 63A-Locking groove; 64-Busset; 641-First bushing; 642-Second bushing; 643-Third bushing; 65-Bracket.

[0057] 7-Drive unit,

[0058] 8-First deceleration mechanism,

[0059] 9-Assist motor,

[0060] 10-Second deceleration mechanism. Detailed Implementation

[0061] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0062] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0063] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0064] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0065] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0066] Figure 1 This is a perspective view of the bottom bracket derailleur. The bottom bracket derailleur of this application is fixedly mounted at the bottom center of the vehicle frame. The bottom bracket derailleur includes a housing 1, a bottom bracket 2, a transmission mechanism 5, a shifting mechanism 6, a drive unit 7, and an output component 4. The housing 1 is fixed to the frame. Except for the output component 4, all other parts are concealed inside the housing 1. Both ends of the bottom bracket 2 extend from the housing 1 and are rotatably supported on the frame. Input components 3 are fixedly connected to both ends of the bottom bracket 2. The input components 3 include a left crank 31 and a right crank 32. The cranks are rotatably connected to pedals. The rider transmits the torque generated by pedaling to the bottom bracket 2, which then inputs it to the transmission mechanism 5. The transmission mechanism 5 is used to adjust the gear ratio and output speed. Different gears are switched by changing the meshing relationship of different planetary gears. The output component 4 is fixed to the transmission mechanism 5 and is used to output torque. The output component 4 then inputs the torque to the flywheel via chain drive, belt drive, or shaft drive, driving the rear wheel of the vehicle to rotate.

[0067] This device can be used on bicycles, folding bicycles, ebikes, electric-assisted bicycles, electric vehicles, electric motorcycles, electric cargo vehicles, tricycles, scooters, electric scooters, and other vehicles.

[0068] Figure 2 This is a perspective view of the outer shell body 11. Figure 3 This is a perspective view of the outer shell 11 from another angle. Figure 4 This is a cross-sectional view of the outer casing body 11. The outer casing 1 includes the outer casing body 11, a first end cap 12, and a second end cap 13. The outer casing body 11 has a columnar structure with openings on both sides. The first end cap 12 and the second end cap 13 are installed at the openings on both sides by screws to achieve internal sealing. The two end caps facilitate the assembly of internal parts. The outer casing body 11 can also be integrally formed with the first end cap 12 or the second end cap 13 to increase structural strength. A mating part 113 is provided on the inner side of the outer casing body 11, which divides the outer casing body 11 into a first receiving cavity 111, a second receiving cavity 112, and a third receiving cavity 114 formed inside the mating part 113.

[0069] The mating part 113 is a ring-shaped structure with a stepped cross-section. Specifically, the cross-sectional shape of the mating part 113 is a two-stage stepped structure. For example... Figure 5 As shown, the mating part 113 includes a first end face 1131, a third circumferential surface 1132, a second end face 1133, a fourth circumferential surface 1134, a third end face 1135, a fifth circumferential surface 1136, a fourth end face 1137, a sixth circumferential surface 1138, and a fifth end face 1139 connected in a clockwise direction. The first end face 1131, the second end face 1133, the third end face 1135, the fourth end face 1137, and the fifth end face 1139 are parallel to each other and are all perpendicular to the X-axis. The third circumferential surface 1132, the fourth circumferential surface 1134, the fifth circumferential surface 1136, and the sixth circumferential surface 1138 are all coaxial and coincide with the X-axis.

[0070] The first receiving cavity 111 is a cavity formed on the first circumferential surface 1111 of the outer shell body 11 and the first end face 1131, third circumferential surface 1132, second end face 1133, fourth circumferential surface 1134, and third end face 1135 of the mating part 113. The first circumferential surface 1111 and the second circumferential surface 1121 are coaxial and coincide with the X-axis. The second receiving cavity 112 is a cavity formed on the second circumferential surface 1121 of the outer shell body 11 and the fifth end face 1139 of the mating part 113. The third receiving cavity 114 is formed by the fifth circumferential surface 1136, fourth end face 1137, and sixth circumferential surface 1138 of the mating part 113. The first receiving cavity 111, the third receiving cavity 114, and the second receiving cavity 112 are connected sequentially. The first receiving cavity 111 is used to accommodate the shifting mechanism 6 of the central shaft transmission and other parts, while the third receiving cavity 114 and the second receiving cavity 112 are used to accommodate the transmission mechanism 5 of the central shaft transmission and other parts. The specific assembly process is described below.

[0071] Planetary gear drives are compact and low-profile, enabling high torque transmission in limited spaces, making them particularly suitable for applications requiring high torque and a compact design. Bicycles demand efficient space utilization for their components; larger components can negatively impact rider maneuverability. Therefore, using planetary gear mechanisms reduces the overall size of the bottom bracket derailleur.

[0072] In this embodiment, the transmission mechanism 5 is a planetary gear mechanism, including a planet carrier 51, planetary gears 53, a sun gear 52, and a ring gear 54. The planetary gears 53 are rotatably supported on the planet carrier 51. The planetary gears 53 externally mesh with the sun gear 52, and the ring gear 54 internally meshes with the planetary gears 53. Multiple planetary gears 53 and sun gears 52 are provided; the more planetary gears 53 and sun gears 52 there are, the more gears the transmission mechanism 5 has. To achieve four gears in the central shaft transmission, such as... Figure 4As shown, the transmission mechanism 5 specifically includes a planetary carrier 51, a first sun gear 521, a second sun gear 522, a third sun gear 523, a gear ring 54, a first planetary gear 531, a second planetary gear 532, and a third planetary gear 533. The connection and meshing relationships of the various parts of the planetary gear mechanism are as follows:

[0073] The first planetary gear 531, the second planetary gear 532, and the third planetary gear 533 are fixedly connected and rotatably supported on the planet carrier 51. The first sun gear 521, the second sun gear 522, and the third sun gear 523 are all rotatably supported on the central shaft 2. The planet carrier 51 is fixedly connected to the central shaft 2. The first planetary gear 531 meshes externally with the first sun gear 521, the second planetary gear 532 meshes externally with the second sun gear 522, and the third planetary gear 533 meshes externally with the third sun gear 523. The gear ring 54 meshes internally with the third planetary gear 533 and is fixedly connected to the output component 4.

[0074] A first clutch assembly 55 is provided between the planetary carrier 51 and the ring gear 54. The first clutch assembly 55 is configured to engage when the rotational speed of the ring gear 54 is lower than or equal to the rotational speed of the planetary carrier 51, causing the ring gear 54 to rotate synchronously with the planetary carrier 51; and disengage when the rotational speed of the ring gear 54 is higher than the rotational speed of the planetary carrier 51, causing the planetary carrier 51 to stop rotating with the ring gear 54. The first clutch assembly 55 can be a roller clutch, a wedge clutch, a pawl clutch, a friction clutch, an electromagnetic clutch, etc.

[0075] To achieve gear shifting, the shifting mechanism 6 locks or releases the sun gear 52 of the planetary gear mechanism. For example... Figures 10-12 As shown, the shifting mechanism 6 includes at least two pawls 61, at least two rotary control members 62, an elastic member (not shown), a bracket 65, and a locking member 63. The rotary control member 62 has a cylindrical structure with a control groove 621 on its outer circumference and a locking member 63 installed on its inner side. The locking member 63 has a disc-shaped structure with a locking groove 63A on its outer circumference. Pawls 61 are installed between the locking member 63 and the rotary control member 62. The pawls 61 are rotatably mounted on the bracket 65, and the bracket 65 is fixed to the outer casing 1.

[0076] Specifically, each pawl 61 has a locking part 61A, a control part 61B, and a rotating shaft part 61C. The rotating shaft part 61C is a circular through hole, which is fitted onto a rotating shaft to allow the pawl 61 to rotate around the shaft. Both the control part 61B and the locking part 61A of the pawl 61 protrude along the thickness direction of the pawl 61. The control part 61B is located on the side opposite to the locking part 61A, and the locking part 61A is used to lock or release with the locking groove 63A of the locking member 63.

[0077] By providing an elastic element on the rotating shaft, the control part 61B of the pawl 61 can be kept in contact with the inner wall of the rotation control member 62. The elastic element can be a torsion spring, with one end of the torsion spring abutting one end of the pawl 61 and the other end of the torsion spring abutting the bracket 65. The torsion spring applies a torque toward the rotation control member 62 to the pawl 61.

[0078] In order to achieve the rotation of the rotary control component 62, an electric shift mechanism is used for driving in this embodiment. The electric shift mechanism includes a drive device 7, which is an encoder motor. The encoder motor can obtain information such as the position, speed and angle of the motor movement in real time through the encoder, and has high measurement accuracy and precision, which is suitable for application scenarios with high requirements for position, speed and angle precision.

[0079] The output end of the drive device 7 is connected to a first reduction mechanism 8, which can be a multi-stage gear reducer. The first reduction mechanism 8 reduces the rotational speed of the drive device 7 and increases the torque, making it easier to overcome the resistance of the pawl 61 to the rotational control member 62 and drive the rotational control member 62 to rotate. The outer circumferential surface of the rotational control member 62 is also provided with gear teeth 622. The first reduction mechanism 8 meshes with the gear teeth 622 of the rotational control member 62 to realize transmission.

[0080] It should be noted that, in addition to the electric shift mechanism, a manual shift mechanism can also be used to drive the rotary control component 62 for shifting.

[0081] Since there are three sun gears 52, there are also three pawls 61, including a first pawl 611, a second pawl 612, and a third pawl 613. The first pawl 611 is closer to the output component 4, and the third pawl 613 is farther away from the output component 4. The first pawl 611, the second pawl 612, and the third pawl 613 are staggered in the circumferential direction. When the rotation control component 62 rotates to a certain angle, only one end of the pawl 61 falls into the control groove 621 and bounces up, while the other pawls 61 remain retracted.

[0082] The number of locking elements 63 corresponds to the number of sun gears 52. There are three locking elements 63, namely the first locking element 631, the second locking element 632 and the third locking element 633. The outer diameters of the first locking element 631, the second locking element 632 and the third locking element 633 are the same, and the inner diameters decrease sequentially.

[0083] Locking element 63 is fixedly connected to the sun gear 52 of transmission mechanism 5. For ease of assembly, such as... Figure 13 and Figure 14As shown, a bushing 64 is provided between the locking member 63 and the sun gear 52. The bushing 64 is a hollow shaft-like part, and its number corresponds to that of the locking member 63. Specifically, the bushing 64 includes a first bushing 641, a second bushing 642, and a third bushing 643. The lengths of the first bushing 641, the second bushing 642, and the third bushing 643 increase sequentially, while their outer diameters decrease sequentially. The three bushings 64 can rotate relative to each other. A rolling bearing can be provided between two adjacent bushings 64 to reduce rolling resistance and ensure load-bearing capacity.

[0084] The bushing 64 can be integrally formed with the sun gear 52 or the locking member 63. In this embodiment, the bushing 64 is integrally formed with the sun gear 52, which ensures the strength of the sun gear 52. The bushing 64 and the locking member 63 are fixed by a spline connection, that is, a spline groove is provided on the inner side of the locking member 63, and a spline is provided on the end of the bushing 64, and the two are assembled together. The bushing 64 and the locking member 63 can also be fixed by other methods, such as square hole connection, threaded connection, etc.

[0085] The assembly process of the three bushings 64 and the three locking parts 63 is as follows:

[0086] Step 1: Fit the second bushing 642 onto the third bushing 643 and install the rolling bearing; fit the first bushing 641 onto the second bushing 642 and install the rolling bearing. Step 2: Assemble the first locking member 631 onto the first bushing 641, the second locking member 632 onto the second bushing 642, and the third locking member 633 onto the third bushing 643. This assembly method ensures structural compactness. A radially compact needle roller bearing can be selected as the rolling bearing.

[0087] The shift mechanism 6 is in the following states during the shifting process: In the initial position, the shift mechanism 6 is in the first gear, such as... Figure 15 As shown, the first pawl 611, the second pawl 612, and the third pawl 613 have not fallen into the control slot 621; the drive device 7 drives the first reduction mechanism 8 to drive the rotation control component 62 of the shift mechanism 6 to rotate counterclockwise, and the shift mechanism 6 is in the second gear position, as shown. Figure 16 As shown, the first pawl 611 and the second pawl 612 did not fall into the control groove 621, only the third pawl 613 fell into the control groove 621; the rotation control component 62 continued to rotate counterclockwise by a certain angle, and the shifting mechanism 6 was in the third gear position, as shown. Figure 17 As shown, the first pawl 611 and the third pawl 613 did not fall into the control groove 621, only the second pawl 612 fell into the control groove 621; the rotation control component 62 continued to rotate counterclockwise by a certain angle, and the shifting mechanism 6 was in the fourth gear position, as shown. Figure 18As shown, the second pawl 612 and the third pawl 613 did not fall into the control groove 621, only the first pawl 611 fell into the control groove 621. The above process is the upshifting process, and the rotation control component 62 rotates in the opposite direction during the downshifting process.

[0088] To facilitate easier installation of the central shaft gearbox into the housing body 11, such as... Figure 6 and Figure 7 As shown, the shifting mechanism 6 and the transmission mechanism 5 of the central shaft gearbox are installed in two steps.

[0089] Step 1: Move the shift mechanism 6 of the central shaft transmission through the first direction ( Figure 4 The rotation control component 62 of the shift mechanism 6 is assembled into the first receiving cavity 111 in the first direction. Specifically, the outer peripheral surface of the rotation control component 62 of the shift mechanism 6 is assembled into the first circumferential surface 1111 of the outer shell body 11 in the first direction, so that the right end face of the rotation control component 62 is aligned with the first end face 1131 with a gap to allow the rotation control component 62 to rotate. The rotation control component 62 cooperates with the mating part 113, that is, the inner and outer peripheral surfaces of the rotation control component 62 are supported by the third circumferential surface 1132 and the first circumferential surface 1111, respectively, and the deformation of the rotation control component 62 caused by the force of the pawl 61 is reduced.

[0090] The bracket 65 of the shift mechanism 6 is assembled onto the fourth circumferential surface 1134 of the outer shell body 11 along the first direction. The two stepped end faces of the bracket 65 are aligned with the second end face 1133 and the third end face 1135, respectively. The bracket 65 is fixed to the outer shell. The bracket 65 can be fixed to the first end cover 12 before assembly.

[0091] Step 2: The transmission mechanism 5 of the central shaft gearbox passes through the second direction ( Figure 4 The first direction (in the N direction) is assembled into the second receiving cavity 112 and the third receiving cavity 114, with the first direction being opposite to the second direction and parallel to the X-axis. Specifically, after the planetary gear mechanism is assembled as a whole, the bushing 64 and the locking member 63 are assembled into the sun gear 52 of the planetary gear mechanism, and assembled into the second circumferential surface 1121 of the outer shell body 11 along the second direction. At this time, the gear ring 54 is located inside the second circumferential surface 1121, the first planetary gear 531 is located inside the fifth circumferential surface 1136, and the second planetary gear 532 is located inside the sixth circumferential surface 1138.

[0092] The transmission mechanism 5 must rotate normally without interfering with the outer shell 11, and the following dimensional relationships must also be met:

[0093] The sum of the addendum circle radius of planetary gear 53 and the center distance of transmission mechanism 5 (planetary gear mechanism) is less than the radius of the third receiving cavity 114. That is, the sum of the addendum circle radius of the first planetary gear 531 and the center distance of the planetary gear mechanism R3 is less than the radius R1 of the fifth circumferential surface 1136, and the sum of the addendum circle radius of the second planetary gear 532 and the center distance of the planetary gear mechanism R4 is less than the radius R2 of the sixth circumferential surface 1138. It should be noted that the center distance of the planetary gear mechanism refers to the distance from the central axis of the planetary gear to the axis of the sun gear. The outer circumferential surface radius of the gear ring 54 is less than the radius of the second circumferential surface 1121.

[0094] This assembly method allows for the installation of the shifting mechanism 6 and the transmission mechanism 5 in two directions by machining only the mating part 113 on the outer shell body 11, thus improving assembly efficiency. The mating part has a simple structure, is easy to machine, and has low manufacturing cost. The mating part 113 supports the rotation control components of the shifting mechanism 6, improving assembly accuracy and reliability.

[0095] Figures 19-22 The rectangular frame of the first clutch assembly 55 is blacked out to indicate that it is in the engaged state, and uncolored to indicate that it is in the disengaged state; the rectangular frame of the pawl 61 is blacked out to indicate that it is in the locked state, and uncolored to indicate that it is in the released state.

[0096] Figure 19 The power transmission path diagram for the first gear of the central shaft transmission is shown.

[0097] As shown in the figure, the shifting mechanism 6 does not lock the sun gear 52, and the first sun gear 521, the second sun gear 522, and the third sun gear 523 can all rotate. The planet carrier 51 and the ring gear 54 rotate at the same speed. The first clutch assembly 55 is engaged, and the torque passes through the central shaft 2, the planet carrier 51, the first clutch assembly 55, the ring gear 54, and the output component 4 in sequence. At this time, the transmission ratio of the transmission mechanism 5 is 1.

[0098] Figure 20 The power transmission path diagram for the second gear of the central shaft transmission is shown.

[0099] As shown in the figure, the shifting mechanism 6 locks the third sun gear 523, while the first sun gear 521 and the second sun gear 522 can rotate. The planetary carrier 51 is the driving gear, the first sun gear 521 is fixed, and the ring gear 54 is the driven gear. This is a speed-increasing transmission with a transmission ratio less than 1. The rotational speed of the ring gear 54 is higher than that of the planetary carrier 51, and the first clutch assembly 55 disengages. The torque passes sequentially through the central shaft 2, planetary carrier 51, third planetary gear 533, third sun gear 523, ring gear 54, and output component 4.

[0100] Figure 21 The diagram shows the power transmission path for the third gear of the central shaft transmission.

[0101] As shown in the figure, the shifting mechanism 6 locks the second sun gear 522, while the first sun gear 521 and the third sun gear 523 can rotate. The planetary carrier 51 is the driving gear, the second sun gear 522 is fixed, and the ring gear 54 is the driven gear. This is a speed-increasing transmission. The transmission ratio of the third gear is less than that of the second gear, and the rotational speed of the ring gear 54 is higher than that of the planetary carrier 51. The first clutch assembly 55 disengages. The torque passes sequentially through the central shaft 2, planetary carrier 51, second planetary gear 532, second sun gear 522, third planetary gear 533, ring gear 54, and output component 4.

[0102] Figure 22 The diagram shows the power transmission path for the fourth gear of the central shaft transmission.

[0103] As shown in the figure, the shifting mechanism 6 locks the first sun gear 521, while the second sun gear 522 and the third sun gear 523 can rotate. The planetary carrier 51 is the driving gear, the first sun gear 521 is fixed, and the ring gear 54 is the driven gear. This is a speed-increasing transmission. The transmission ratio of the fourth gear is less than that of the third gear, and the rotational speed of the ring gear 54 is higher than that of the planetary carrier 51. The first clutch assembly 55 disengages. The torque passes sequentially through the central shaft 2, planetary carrier 51, first planetary gear 531, first sun gear 521, third planetary gear 533, ring gear 54, and output component 4.

[0104] This application also provides a mid-drive motor, including the aforementioned mid-shaft gearbox, enabling the mid-drive motor to have both shifting and electric assist functions. For example... Figures 23-25 As shown, the difference from the central shaft gearbox lies in the addition of an assist motor 9 and a second reduction mechanism 10. The assist motor 9 can be connected to the central shaft 2 or to the transmission mechanism 5. The connection method can be any of chain drive, belt drive, or gear drive. In this embodiment, the assist motor 9 and the transmission mechanism 5 are connected via gear drive. Specifically, the axis of the output shaft of the assist motor 9 is parallel to the axis of the central shaft 2. The parallel arrangement structure is simple and easy to assemble and maintain. The assist motor 9 can be directly connected to the transmission mechanism 5, or it can be connected to the gear ring 54 of the transmission mechanism 5 through the second reduction mechanism 10. The second reduction mechanism 10 can be a planetary gear reduction mechanism.

[0105] A second clutch assembly 56 is provided between the assist motor 9 and the gear ring 54. The assist motor 9 is connected to a second reduction mechanism 10. The second clutch assembly 56 can be located between the second reduction mechanism 10 and the gear ring 54. The second clutch assembly 56 is configured to engage when the speed of the gear ring 54 is lower than or equal to the speed of the second reduction mechanism 10, causing the gear ring 54 to rotate synchronously with the second reduction mechanism 10. When the speed of the gear ring 54 is higher than the speed of the second reduction mechanism 10, the clutch assembly 56 disengages, and the second reduction mechanism 10 does not rotate with the gear ring 54. The function of the second clutch assembly 56 is that when the battery supplying power to the assist motor 9 is depleted, the assist motor 9 does not work, the speed of the second reduction mechanism 10 is zero, the second clutch assembly 56 disengages, and the rider's pedaling will only drive the transmission mechanism 5 to rotate, not the assist motor 9 and the second reduction mechanism 10, thus reducing riding resistance.

[0106] When the assist motor 9 is working, in addition to the torque generated by the rider's pedaling, there is also the torque generated by the assist motor 9. The combined torque of the two is output to the output component 4, enabling the rider to achieve higher riding speed or longer riding distance in a less strenuous way.

[0107] A mid-drive motor with shifting function, compared to a rear-drive motor (hub motor) with shifting function, has a shifting structure on the frame instead of the rear wheel. When impacted on rough roads, the impact is not directly transmitted to the hub through the rim and spokes, but is transmitted through the frame. The frame has a certain vibration absorption function, which greatly reduces the impact force. It is relatively less affected by external forces and less prone to bumps, making the mid-drive motor more durable.

[0108] The weight of a rear-mounted motor is concentrated on the rear wheel, which is not conducive to the vehicle's take-off and jumping. In contrast, the weight of a mid-mounted motor is concentrated on the lower part of the frame's center of gravity, which has less impact on the overall balance of the vehicle and can greatly improve handling performance.

[0109] Vehicles equipped with a mid-mounted gearbox also feature a speed feedback system. For example, a GPS chip is added to obtain location information and calculate the vehicle's speed. In automatic mode, the rider requires no operation; the mid-mounted gearbox shifts gears based on the vehicle's speed. For instance, when the speed reaches 10 km / h, it automatically shifts from first to second gear; conversely, when the speed drops below 10 km / h, it automatically shifts from second to first gear. Riders can switch to manual mode to freely change gears based on actual road conditions, increasing riding flexibility, or switch to free mode for automatic gear changes, enhancing riding comfort.

[0110] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with the described embodiment or example is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0111] The above descriptions are merely some embodiments of this utility model. For those skilled in the art, various modifications and improvements can be made without departing from the inventive concept of this utility model, and all such modifications and improvements fall within the protection scope of this utility model.

Claims

1. A casing, characterized in that, The system includes a housing body (11), an inner side of which is provided with a mating part (113), which divides the housing body (113) into a first receiving cavity (111) and a second receiving cavity (112), and a third receiving cavity (114) formed inside the mating part (113). The shifting mechanism (6) of the central shaft transmission is assembled to the first receiving cavity (111) in a first direction, and the transmission mechanism (5) of the central shaft transmission is assembled to the second receiving cavity (112) and the third receiving cavity (114) in a second direction, wherein the first direction is opposite to the second direction.

2. The outer casing according to claim 1, characterized in that, The cross-sectional shape of the mating part (113) is stepped.

3. The outer casing according to claim 2, characterized in that, The mating part (113) includes a first end face (1131), a third circumferential surface (1132), a second end face (1133), a fourth circumferential surface (1134), and a third end face (1135) connected in sequence. The outer shell body (11) is provided with a first circumferential surface (1111). The first circumferential surface (1111), the first end face (1131), the third circumferential surface (1132), the second end face (1133), the fourth circumferential surface (1134), and the third end face (1135) form the first receiving cavity (111).

4. The outer casing according to claim 3, characterized in that, The shifting mechanism (6) includes at least two pawls (61), at least two locking members (63), an elastic member, a bracket (65), and a rotation control member (62). The pawls (61) are rotatably mounted on the bracket (65). One end of the elastic member abuts against the bracket (65), and the other end of the elastic member abuts against the pawls (61). The outer circumferential surface of the rotation control member (62) is provided with a control groove (621). The pawls (61) are disposed between the locking members (63) and the rotation control member (62). The locking members (63) are fixedly connected to the sun gear (52) of the transmission mechanism (5). When the rotation control member (62) rotates to a specific angle, one end of the pawls (61) falls into the control groove (621), locking the pawls (61) and the locking members (63) to change the transmission ratio. The rotation control element (62) and the bracket (65) are assembled in the first receiving cavity (111).

5. The outer casing according to claim 2, characterized in that, The mating part (113) includes a fifth end face (1139), a sixth circumferential face (1138), a fourth end face (1137), and a fifth circumferential face (1136) connected in sequence. The outer shell body (11) is provided with a second circumferential face (1121). The fifth end face (1139) and the second circumferential face (1121) form a second receiving cavity (112). The sixth circumferential face (1138), the fourth end face (1137), and the fifth circumferential face (1136) form a third receiving cavity (114).

6. The outer casing according to claim 5, characterized in that, The transmission mechanism (5) includes a planet carrier (51), a planetary gear (53), a sun gear (52), and a gear ring (54). The planetary gear (53) is rotatably supported on the planet carrier (51). The planetary gear (53) meshes externally with the sun gear (52), and the gear ring (54) meshes internally with the planetary gear (53). The planet carrier (51), the planetary gear (53), the sun gear (52), and the ring gear (54) are assembled in the second receiving cavity (112) and the third receiving cavity (114).

7. The outer casing according to claim 6, characterized in that, The sum of the tip circle radius of the planetary gear (53) and the center distance of the transmission mechanism (5) is less than the radius of the third receiving cavity (114).

8. A mid-shaft transmission, characterized in that, Including the housing (1) as described in any one of claims 1-7, further comprising: A central axle (2) is rotatably supported on the frame, and torque is input from the central axle (2); The transmission mechanism (5) includes a planetary carrier (51) connected to the central shaft (2), through which torque passes, and the transmission mechanism (5) has at least two transmission ratios. The shifting mechanism (6) is linked with the transmission mechanism (5) and is used to change the transmission ratio of the transmission mechanism (5); The drive unit (7) is connected to the shifting mechanism (6); The output component (4) is connected to the transmission mechanism (5) to output torque; The transmission mechanism (5), the shifting mechanism (6), and the drive device (7) are installed inside the housing (1).

9. A mid-drive motor, characterized in that, The system includes the central shaft transmission as described in claim 8, and also includes a power assist motor (9) connected to the central shaft (2) or the transmission mechanism (5).

10. The mid-mounted motor according to claim 9, characterized in that, The auxiliary motor (9) is set on an axis parallel to the central shaft (2).

11. The mid-mounted motor according to claim 9, characterized in that, The power assist motor (9) is connected to the central shaft (2) or the transmission mechanism (5) via any one of chain drive, belt drive, or gear drive.

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