A gear drive based mid-motor

Abstract

This invention discloses a gear-driven mid-drive motor in the field of motor technology, comprising: a motor body; a central shaft with crank assemblies at both ends; a gearbox for transmitting power from the output shaft of the motor body to the central shaft; and a mounting bracket for supporting the rotation of the central shaft and for mounting the gearbox. The gearbox and mounting bracket are detachably connected to allow for replacement of gearboxes with different gear ratios. The gearbox has an output shaft through-hole and a central shaft through-hole. The gear in the output shaft through-hole slides axially with the output shaft of the motor body, forming a separable power connection. Similarly, the gear in the central shaft through-hole slides axially with the central shaft, forming a separable power connection. The modular design of the mid-drive motor gearbox enhances product versatility. Users can quickly replace gearboxes with different gear ratios according to their needs. Furthermore, the detachable design of the gearbox eliminates the need for tools, making the entire operation convenient and fast.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and more specifically to a mid-drive motor based on gear drive. Background Technology

[0002] With the increasing popularity of electric bicycles, electric bikes, and shared electric vehicles, users are demanding higher and higher levels of comfort, power performance, and maintainability.

[0003] The gearboxes of existing mid-drive motors are usually of a single-piece structure, requiring the disassembly of the crank or bottom bracket assembly during installation. This cumbersome replacement process demands a high level of user skill, limiting the development of modular gearbox replacement and multi-ratio adaptation. Different usage scenarios (such as commuting, heavy-duty riding, and off-road riding) have significantly different gear ratio requirements, while existing motor systems typically only have a single-ratio gearbox, making it difficult to meet users' personalized needs for different road conditions and riding habits, thus limiting the user experience.

[0004] To address these issues, a mid-drive motor based on gear drive is provided. Summary of the Invention

[0005] The purpose of this invention is to provide a mid-drive motor based on gear drive, which solves the problem that existing mid-drive motors with gear transmissions are mostly fixed structures and cannot meet the needs of different scenarios.

[0006] The present invention achieves the above objectives through the following technical solutions: A gear-driven mid-drive motor, comprising: Motor body; A central shaft, with crank assemblies at both ends; The gearbox is used to transmit the power from the output shaft of the motor body to the central shaft; The mounting bracket is used to support the rotation of the central shaft and to mount the gearbox, which is detachably connected to the mounting bracket to allow for the replacement of gearboxes with different gear ratios.

[0007] The gearbox has an output shaft through hole and a central shaft through hole. The gear in the output shaft through hole slides axially with the output shaft of the motor body to form a separable power connection. The gear in the central shaft through hole slides axially with the central shaft to form a separable power connection. The top of the gearbox has a sliding groove, and the mounting bracket has a slide rail that matches the sliding groove. The top of the gearbox also has a limiting groove, and the mounting bracket has an elastically retractable limiting member that is inserted into the limiting groove to limit the axial displacement of the gearbox in the installed state. The side of the gearbox has a handle groove.

[0008] As a further optimization of the present invention, a first wedge block is provided in the limiting groove; the limiting member includes a fixed seat, a movable rod movably disposed through the fixed seat, and a second wedge block and a top block fixedly disposed at both ends of the movable rod, and a spring is sleeved on the movable rod between the second wedge block and the fixed seat; the first wedge block squeezes the second wedge block to push the limiting member upward and automatically insert it into the limiting groove.

[0009] As a further optimization of the present invention, the gearbox is a split-type gearbox structure, including a first gearbox and a second gearbox; the output shaft through hole is provided on the first gearbox, and the central shaft through hole is composed of two semi-circular groove structures, which are respectively provided at the splice joint of the first gearbox and the second gearbox.

[0010] As a further optimization of the present invention, it also includes a storage box for storing multiple gearboxes with different gear ratios. The storage box is fixedly mounted on the vehicle body and is provided with multiple mounting slots.

[0011] As a further optimization of the present invention, it also includes a locking member for passing through the gearbox, the limiting member, and the mounting bracket to limit the radial displacement of the gearbox; the locking member includes a plate, the lower part of which is provided with a positioning pin, and the gearbox, the limiting member, and the mounting bracket are all provided with positioning holes that match the positioning pin.

[0012] As a further optimization of the present invention, the locking member is also used to lift the limiting member to release its limitation on the gearbox; the upper part of the plate is slidably disposed in the top groove of the mounting bracket, and a rotating shaft is fixedly disposed on the plate; the side wall of the top groove of the mounting bracket is provided with a slot hole that matches the rotating shaft; the upper bottom surface of the plate is provided with an elastic hook, and the top block is provided with a hook groove that matches the elastic hook; the plate rotates to lift the limiting member.

[0013] As a further optimization of the present invention, a locking block is provided at one end of the upper part of the plate, and a slot that engages with the locking block is provided at the corresponding position in the groove at the top of the mounting bracket.

[0014] As a further optimization of the present invention, it also includes a rotation adjustment mechanism for driving the mounting bracket to rotate to adjust the height of the central shaft; the rotation adjustment mechanism includes a support bracket fixedly mounted on the vehicle body, an arc-shaped rack rotatably mounted on the support bracket, and a drive unit for driving the arc-shaped rack to rotate, wherein the axis of the arc-shaped rack coincides with the axis of the output shaft of the motor body, and the mounting bracket is fixedly mounted on the arc-shaped rack.

[0015] As a further optimization of the present invention, the rotation angle of the mounting bracket is ±20°.

[0016] As a further optimization of the present invention, the drive unit includes a first gear meshing with an arc-shaped rack, a second gear meshing with the first gear, and a spur rack meshing with the second gear; the first gear and the second gear are both rotatably mounted on a support frame, the spur rack is slidably mounted on the support frame, a connecting frame is fixedly mounted on the spur rack, and the connecting frame is fixedly mounted on the seat lifting rod to automatically adjust the center shaft height when the seat height is adjusted.

[0017] The beneficial effects of this invention are as follows: 1. The modular design of the gearbox in this invention improves the product's versatility. Users can quickly replace gearboxes with different gear ratios according to their needs. Furthermore, the detachable design of the gearbox makes the entire operation tool-free, convenient, and fast.

[0018] 2. This invention enables the mounting bracket to rotate around the axis of the motor body's output shaft via a rotary adjustment mechanism, thereby adjusting the height of the bottom bracket. This design improves riding comfort and is suitable for people of different heights. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of the overall structure of the present invention. Figure 1 ; Figure 2 This is a three-dimensional schematic diagram of the overall structure of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the connection structure between the gearbox and the mounting bracket of the present invention. Figure 1 ; Figure 4 This is a schematic diagram of the connection structure between the gearbox and the mounting bracket of the present invention. Figure 2 ; Figure 5 This is a schematic diagram of the gearbox structure of the present invention; Figure 6 This is a cross-sectional view of the gearbox, mounting bracket, and locking component connection structure of the present invention; Figure 7 This is a schematic diagram of the rotary adjustment mechanism of the present invention.

[0020] In the picture: 1. Motor body; 2. Gearbox; 201. First gearbox housing; 202. Second gearbox housing; 203. Output shaft through hole; 204. Central shaft through hole; 205. Handle groove; 206. Slide groove; 207. Limiting groove; 208. First wedge block; 3. Mounting bracket; 301. Limiting component; 301a. Fixed base; 301b. Movable rod; 301c. Second wedge block; 301d. Spring; 301e. Top block; 301f. 302. Hook groove; 303. Slot; 4. Central shaft; 5. Rotation adjustment mechanism; 501. Support frame; 502. Arc rack; 503. First gear; 504. Second gear; 505. Straight rack; 506. Connecting frame; 6. Locking component; 601. Plate; 602. Positioning pin; 603. Rotating shaft; 604. Locking block; 605. Elastic hook; 7. Storage box; 701. Mounting slot; 8. Crank assembly. Detailed Implementation

[0021] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content.

[0022] Example 1 To address the issue that existing mid-drive motor gear drives mostly have fixed structures with invariable gear ratios, failing to meet the needs of different scenarios, please refer to... Figures 1-3 , Figure 5 The present invention provides a mid-drive motor based on gear drive, comprising: Motor body 1; Central shaft 4, with crank assemblies 8 at both ends; Gearbox 2 is used to transmit the power from the output shaft of motor body 1 to the central shaft 4; Mounting bracket 3 is used to support the rotation of the central shaft 4 and to mount the gearbox 2. The mounting bracket 3 is equipped with a bearing for supporting the central shaft 4. The gearbox 2 and the mounting bracket 3 are detachably connected to allow for the replacement of gearboxes 2 with different gear ratios. In order to improve the overall neatness of the appearance, the side of the mounting bracket 3 is provided with a notch groove that matches the shape of the gearbox 2. When the gearbox 2 is slidably mounted on the mounting bracket 3, the gearbox 2 and the mounting bracket 3 together form an approximately cuboid overall structure.

[0023] The gearbox 2 has an output shaft through hole 203 and a central shaft through hole 204. The gear in the output shaft through hole 203 is axially slidingly engaged with the output shaft of the motor body 1 to form a separable power connection. The gear in the central shaft through hole 204 is axially slidingly engaged with the central shaft 4 to form a separable power connection. The top of the gearbox 2 has a slide groove 206, and the mounting bracket 3 has a slide rail that matches the slide groove 206 to guide the gearbox 2 to slide along a predetermined trajectory. The slide groove 206 has a T-shaped cross section to limit the radial displacement of the gearbox 2. The top of the gearbox 2 also has a limiting groove 207, and the mounting bracket 3 has an elastically retractable limiting member 301. The limiting member 301 is inserted into the limiting groove 207 to limit the axial displacement of the gearbox 2 in the installed state. The side of the gearbox 2 has a handle groove 205 to assist the user in disassembling or replacing the gearbox 2.

[0024] like Figure 6 As shown, a first wedge block 208 is provided in the limiting groove 207; the limiting member 301 includes a fixed base 301a, a movable rod 301b movably passing through the fixed base 301a, and a second wedge block 301c and a top block 301e fixed at both ends of the movable rod 301b. A spring 301d is sleeved on the movable rod 301b between the second wedge block 301c and the fixed base 301a; the first wedge block 208 presses the second wedge block 301c to push the limiting member 301 upward and automatically insert it into the limiting groove 207.

[0025] When the gearbox 2 is slidably installed onto the mounting bracket 3 along the slide rail, the second wedge block 301c cooperates with the first wedge block 208, pushing the limiting member 301 upward and compressing the spring 301d. After the gearbox 2 is fully installed, the limiting groove 207 aligns with the limiting member 301, and the spring 301d releases energy to push the limiting member 301 to automatically insert into the limiting groove 207, achieving automatic locking and axial limiting of the gearbox 2. The limiting member 301 can automatically lock the gearbox 2 during installation, avoiding the risk of improper installation or loosening during operation. This structure can complete the locking without additional operation, greatly improving installation efficiency and safety.

[0026] To enable gearbox 2 replacement without disassembling crank assembly 8, thereby improving replacement efficiency, such as... Figure 3As shown, the gearbox 2 is a split-type housing structure, including a first housing 201 and a second housing 202. The output shaft through-hole 203 is located on the first housing 201, and the central shaft through-hole 204 consists of two semi-circular grooves located at the joint between the first housing 201 and the second housing 202. When the first housing 201 and the second housing 202 are joined, the central shaft through-hole 204 forms a complete through hole for accommodating the central shaft 4. This eliminates the need to disassemble the crank assembly 8 when replacing the gearbox 2, significantly improving replacement efficiency and user experience, and reducing maintenance costs. It is particularly suitable for scenarios requiring frequent configuration changes, such as shared electric vehicles, the rental market, and family-shared vehicles.

[0027] like Figure 7 As shown, the vehicle also includes a storage box 7 for storing multiple gearboxes 2 with different gear ratios. The storage box 7 is fixed to the vehicle body and has multiple mounting slots 701, each of which is used to store a gearbox 2 with a specific gear ratio. The gearbox 2 uses a planetary gear structure or helical gear set to achieve different gear ratio settings. For example, the commuter gearbox 2 (gear ratio of 1:5) is suitable for high efficiency and energy saving, and is suitable for daily commuting. The heavy-duty gearbox 2 (gear ratio of 1:8) is suitable for high torque requirements and is suitable for high load conditions such as carrying goods or passengers. The off-road gearbox 2 (gear ratio of 1:10) is suitable for strong climbing performance and is suitable for mountain riding or outdoor adventure. The multi-gearbox 2 design makes the mid-drive motor adaptable to multiple scenarios, such as outdoor riding, with quick switching between climbing, flat road, and downhill scenarios. For example, in family shared vehicles, one vehicle can meet the different needs of the elderly (low speed, high torque) and young people (high speed, high efficiency).

[0028] During installation, the user holds the gearbox 2 through the handle groove 205, aligns the T-shaped slide groove 206 on its top with the slide rail of the mounting bracket 3, and slides it axially along the predetermined trajectory. During the sliding process, the gear in the output shaft through hole 203 gradually meshes with the output shaft of the motor body 1 through the axial sliding structure, and the gear in the central shaft through hole 204 meshes synchronously with the central shaft 4. When the gearbox 2 slides to the installation position, the limiting piece 301 on the mounting bracket 3 automatically springs into the limiting groove 207 under the action of elastic force, completing the axial locking. At this time, the gearbox 2, the mounting bracket 3, the motor body 1, and the central shaft 4 form a stable power transmission structure.

[0029] During power transmission, the output shaft of the motor body 1 rotates, and the power is transmitted to the gearbox 2 through the gear in the output shaft through hole 203. After the gearbox 2 with different gear ratios achieves different deceleration / speed-up effects through the internal gear set, the power is transmitted to the central shaft 4 through the gear in the central shaft through hole 204. The central shaft 4 drives the crank assemblies 8 at both ends to rotate, and finally drives the vehicle forward.

[0030] When replacing or disassembling, the user lifts the limiting piece 301 to disengage it from the limiting groove 207, and pulls the gearbox 2 outward through the handle groove 205. The gear in the output shaft through hole 203 and the gear in the central shaft through hole 204 disengage from the output shaft of the motor body 1 and the central shaft 4, respectively, and the gearbox 2 can be removed. When replacing the new gearbox 2, the installation process is repeated. The whole operation does not require tools and is convenient and fast.

[0031] Example 2 Based on Example 1, in order to further improve the installation stability of gearbox 2, such as Figure 4 , Figure 6 As shown, it also includes a locking member 6 for passing through the gearbox 2, the limiting member 301 and the mounting bracket 3 to limit the radial displacement of the gearbox 2; the locking member 6 includes a plate 601, the lower part of the plate 601 is provided with a positioning pin 602, and the gearbox 2, the limiting member 301 and the mounting bracket 3 are all provided with positioning holes that match the positioning pin 602.

[0032] The locking member 6 is also used to lift the limiting member 301 to release its limitation on the gearbox 2; the upper part of the plate 601 is slidably disposed in the top groove of the mounting bracket 3, and a rotating shaft 603 is fixedly disposed on the plate 601. The side wall of the top groove of the mounting bracket 3 is provided with a slot 302 that matches the rotating shaft 603; the upper bottom surface of the plate 601 is provided with an elastic hook 605, and the top block 301e is provided with a hook groove 301f that matches the elastic hook 605. The plate 601 rotates to lift the limiting member 301.

[0033] Furthermore, a locking block 604 is provided at one end of the upper part of the plate 601, and a slot 303 is provided at the corresponding position in the groove at the top of the mounting bracket 3 to engage with the locking block 604.

[0034] After the gearbox 2 is installed, the locking member 6, through its lower positioning pin 602, is sequentially inserted into the positioning holes on the gearbox 2, the limiting member 301, and the mounting bracket 3 to achieve limiting and locking of the gearbox 2, preventing displacement or detachment during operation. At this time, the plate 601 of the locking member 6 engages with the slot 303 in the groove at the top of the mounting bracket 3 via the end block 604, achieving limiting and fixing of the locking member 6 in the installed state, thereby ensuring the installation stability and operational safety of the gearbox 2. When the gearbox 2 needs to be replaced, the user pulls the plate 601 of the locking member 6 outward, causing the block 604 to disengage from the slot 303, and simultaneously driving the rotating shaft 603 to slide along the slot 302 on the side wall of the groove at the top of the mounting bracket 3, so that the positioning pin 602 gradually disengages from the gearbox 2, the limiting member 301, and the mounting bracket 3. The positioning hole; when the plate 601 is pulled to the outermost position, the positioning pin 602 completely disengages from the positioning hole. At this time, the elastic hook 605 at the bottom of the locking part 6 is engaged in the hook groove 301f on the top block 301e. Then, the user pulls the plate 601 upward to make it rotate around the rotating shaft 603, which drives the elastic hook 605 to lift the limiting part 301 upward, thereby releasing the limiting effect of the limiting part 301 on the gearbox 2. At this time, the gearbox 2 can slide outward along the slide rail direction to complete the disassembly operation. The whole process does not require the use of tools, and the operation is simple, safe and reliable.

[0035] Example 3 Based on Embodiments 1 and 2, in order to solve the problem of poor adaptability to riding posture caused by the fixed height of the central shaft 4 in the existing mid-drive motor structure, such as... Figure 7 As shown, it also includes a rotation adjustment mechanism 5 for driving the mounting bracket 3 to rotate to adjust the height of the central shaft 4; the rotation adjustment mechanism 5 includes a support bracket 501 fixed on the vehicle body, an arc-shaped rack 502 rotatably mounted on the support bracket 501, and a drive unit for driving the arc-shaped rack 502 to rotate. The axis of the arc-shaped rack 502 coincides with the axis of the output shaft of the motor body 1. The mounting bracket 3 is fixed on the arc-shaped rack 502, and the rotation angle of the mounting bracket 3 is ±20°.

[0036] The drive unit includes a first gear 503 meshing with an arc-shaped rack 502, a second gear 504 meshing with the first gear 503, and a spur rack 505 meshing with the second gear 504; the first gear 503 and the second gear 504 are both rotatably mounted on the support frame 501, the spur rack 505 is slidably mounted on the support frame 501, and a connecting frame 506 is fixedly mounted on the spur rack 505. The connecting frame 506 is fixedly mounted on the seat lifting rod to automatically adjust the height of the central shaft 4 when the seat height is adjusted.

[0037] When the user adjusts the seat height, the seat lifting rod moves the connecting frame 506. The connecting frame 506 pushes the rack 505 to slide along the support frame 501. The rack 505 drives the arc rack 502 to rotate through the second gear 504 and the first gear 503, thereby driving the mounting frame 3 to rotate and adjusting the height of the central shaft 4. After the height of the central shaft 4 is adjusted, the chain tension between the crank assembly 8 and the wheel also changes accordingly. A tensioning wheel can be provided at the chain to adapt to the change in chain tension and ensure the normal operation of the transmission system. This part of the structure is a conventional technical means in this field, so its specific structure will not be described in detail here.

[0038] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A mid-drive motor based on gear drive, characterized in that, include: Motor body (1); A central shaft (4) is provided at both ends of which crank assemblies (8); Gearbox (2) is used to transmit the power from the output shaft of the motor body (1) to the central shaft (4). Mounting bracket (3) is used to support the rotation of the central shaft (4) and to mount the gearbox (2). The gearbox (2) and mounting bracket (3) are detachably connected to each other to replace gearboxes (2) with different gear ratios. The gearbox (2) is provided with an output shaft through hole (203) and a central shaft through hole (204). The gear in the output shaft through hole (203) slides axially with the output shaft of the motor body (1) to form a separable power connection. The gear in the central shaft through hole (204) slides axially with the central shaft (4) to form a separable power connection. The top of the gearbox (2) is provided with a slide groove (206), and the mounting bracket (3) is provided with a slide rail that matches the slide groove (206); The top of the gearbox (2) is also provided with a limiting groove (207), and the mounting bracket (3) is provided with a retractable limiting member (301). The limiting member (301) is inserted into the limiting groove (207) to limit the axial displacement of the gearbox (2) in the installed state. The gearbox (2) has a handle groove (205) on its side.

2. A mid-drive motor based on gear drive according to claim 1, characterized in that, The limiting groove (207) is provided with a first wedge block (208); The limiting member (301) includes a fixed base (301a), a movable rod (301b) movably passing through the fixed base (301a), and a second wedge block (301c) and a top block (301e) fixed at both ends of the movable rod (301b). A spring (301d) is sleeved on the movable rod (301b) between the second wedge block (301c) and the fixed base (301a). The first wedge (208) presses against the second wedge (301c) to push the limiting member (301) upward and automatically insert it into the limiting groove (207).

3. A mid-drive motor based on gear drive according to claim 1, characterized in that, The gearbox (2) is a split-type gearbox structure, including a first gearbox (201) and a second gearbox (202). The output shaft through hole (203) is provided on the first housing (201), and the central shaft through hole (204) is composed of two semi-circular groove structures, which are respectively provided at the splice seam of the first housing (201) and the second housing (202).

4. A mid-drive motor based on gear drive according to claim 1, characterized in that, It also includes a storage box (7) for storing multiple gearboxes (2) with different gear ratios, the storage box (7) being fixedly mounted on the vehicle body and having multiple mounting slots (701).

5. A mid-drive motor based on gear drive according to claim 2, characterized in that, It also includes a locking element (6) for passing through the gearbox (2), the limiting element (301) and the mounting bracket (3) to limit the radial displacement of the gearbox (2); The locking component (6) includes a plate (601), and a positioning pin (602) is provided at the lower part of the plate (601). The gearbox (2), the limiting component (301), and the mounting bracket (3) are all provided with positioning holes that match the positioning pin (602).

6. A mid-drive motor based on gear drive according to claim 5, characterized in that, The locking member (6) is also used to lift the limiting member (301) to release its limitation on the gearbox (2); The upper part of the plate (601) is slidably disposed in the top groove of the mounting bracket (3), and a rotating shaft (603) is fixedly disposed on the plate (601). The side wall of the top groove of the mounting bracket (3) is provided with a slot (302) that matches the rotating shaft (603). The upper bottom surface of the plate (601) is provided with an elastic hook (605), and the top block (301e) is provided with a hook groove (301f) that matches the elastic hook (605). The plate (601) rotates to lift the limiting member (301).

7. A mid-drive motor based on gear drive according to claim 6, characterized in that, The upper end of the plate (601) is provided with a locking block (604), and the mounting bracket (3) is provided with a corresponding slot (303) in the top groove to engage with the locking block (604).

8. A mid-drive motor based on gear drive according to claim 1, characterized in that, It also includes a rotation adjustment mechanism (5) for driving the mounting bracket (3) to rotate to adjust the height of the central shaft (4); The rotation adjustment mechanism (5) includes a support frame (501) fixed on the vehicle body, an arc rack (502) rotatably mounted on the support frame (501), and a drive unit for driving the arc rack (502) to rotate. The axis of the arc rack (502) coincides with the axis of the output shaft of the motor body (1), and the mounting bracket (3) is fixed on the arc rack (502).

9. A mid-drive motor based on gear drive according to claim 8, characterized in that, The rotation angle of the mounting bracket (3) is ±20°.

10. A mid-drive motor based on gear drive according to claim 9, characterized in that, The drive unit includes a first gear (503) meshing with an arc-shaped rack (502), a second gear (504) meshing with the first gear (503), and a straight rack (505) meshing with the second gear (504). The first gear (503) and the second gear (504) are both rotatably mounted on the support frame (501). The rack (505) is slidably mounted on the support frame (501). A connecting frame (506) is fixedly mounted on the rack (505). The connecting frame (506) is fixedly mounted on the seat lifting rod so as to automatically adjust the height of the central shaft (4) when the seat height is adjusted.

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