Middle motor with high waterproof grade
By employing a labyrinth seal structure at the rotating connection of the mid-drive motor, the problem of insufficient waterproof performance of traditional mid-drive motors is solved, achieving an IPX7 waterproof rating. The structure is compact and requires no additional sealing materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANDE FIVE-STAR VEHICLE IND CO LTD
- Filing Date
- 2025-04-22
- Publication Date
- 2026-04-17
AI Technical Summary
Traditional mid-drive motors cannot meet high-level waterproof requirements, such as IPX7, and existing sealing designs are not effective in preventing the erosion of rainwater and mud.
The labyrinth seal structure forms a high-waterproof level seal at three rotating connections: between the first housing and the main shaft, the second housing and the output shaft sleeve, and the output shaft sleeve and the main shaft. It includes a first, second, and third labyrinth seal structure and utilizes multiple tortuous chambers and sealing teeth design to reduce leakage.
It achieves a high level of waterproof sealing, reliably ensuring the waterproof performance of rotating joints, reaching the IPX7 standard, with a compact structure and no need for additional sealing materials.
Smart Images
Figure CN224138808U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of mid-drive motor technology, specifically relating to a high waterproof mid-drive motor. Background Technology
[0002] The mid-drive motor is the core component of an electric-assist bicycle. Electric-assist bicycles equipped with a mid-drive motor can freely switch between assisted riding mode and manual riding mode. The assisted riding mode offers advantages such as promoting exercise and providing extended battery life.
[0003] A typical mid-drive motor includes a housing, a motor body, an output shaft, and a torque sensor assembly. The torque sensor assembly consists of the torque sensor body and a bottom shaft located within the housing. The front end of the bottom shaft passes through the output shaft, and the rear end passes through the torque sensor body. The bottom shaft is connected to the output shaft via a clutch. During use, the rider pedals, causing the bottom shaft to rotate. The torque sensor body transmits the torque generated by the pedaling motion to the controller, which then controls the motor body to provide proportional drive torque to the output shaft. The higher the pedaling torque, the greater the output torque of the motor body, thus providing assisted riding.
[0004] Since mid-drive motors are typically installed at the bottom of vehicles, they are susceptible to corrosion from rain, mud, and other external environmental factors. Therefore, waterproofing performance is a crucial indicator for mid-drive motors. However, traditional waterproofing designs, which often employ sealing rings, waterproof adhesives, and interference fits, are insufficient to meet high-level waterproofing requirements (such as IPX7). Summary of the Invention
[0005] This invention addresses the shortcomings of existing mid-drive motors in electric bicycles, which often fail to meet high-level waterproofing requirements, by providing a mid-drive motor with a high waterproofing rating.
[0006] To achieve the above objectives, this utility model adopts the following technical solution: a high waterproof rating mid-drive motor, wherein the high waterproof rating mid-drive motor comprises:
[0007] Gear motor body;
[0008] The outer casing includes a first casing and a second casing that are axially distributed;
[0009] The sensor assembly includes a spindle and a torque sensor on the spindle, with the torque sensor located inside the housing and both ends of the spindle located outside the housing.
[0010] The output shaft sleeve is driven by the geared motor body, with one end located inside the housing and the other end located outside the housing;
[0011] The first housing and the main shaft form a first labyrinth seal structure, the second housing and the output shaft sleeve form a second labyrinth seal structure, and the output shaft sleeve and the main shaft form a third labyrinth seal structure.
[0012] This utility model relates to a high-waterproof mid-drive motor. The three rotating connections—between the first housing and the main shaft, between the second housing and the output shaft sleeve, and between the output shaft sleeve and the main shaft—all employ labyrinth seal structures, reliably ensuring a high level of waterproof sealing at these connections. A labyrinth seal is a seal created by numerous tortuous chambers between rotating and stationary parts to reduce leakage. The labyrinth seal has several sequentially arranged annular sealing teeth around the shaft, forming a series of flow-blocking gaps and expansion cavities between the teeth. The sealed medium experiences a throttling effect as it passes through the gaps in the labyrinth, thus preventing leakage.
[0013] As an improvement, the first labyrinth sealing structure includes a first fixed ring on the first housing, a first rotating ring on the main shaft, a first sealing ring between the first fixed ring and the first rotating ring, and a second sealing ring between the first rotating ring and the main shaft. The first sealing ring and the second sealing ring are axially distributed, and a first sealing tooth is formed on the inner side of the first fixed ring and a second sealing tooth is formed on the outer side of the first rotating ring.
[0014] As an improvement, the first sealing tooth portion includes, from the outside to the inside, a first inner groove, a first inner tooth, a second inner groove, and a second inner tooth in sequence. The radial depth of the first inner groove is greater than that of the second inner groove. The end face of the first inner tooth is inclined relative to the main shaft axis and the outer end is closer to the main shaft axis than the inner end. The axial inner end face of the second inner tooth is parallel to the main shaft axis.
[0015] The second sealing tooth portion includes, from the outside to the inside, a first external tooth, a first external groove, a second external tooth, a second external groove, and a third external tooth. The axial outer end faces of the first and third external teeth are parallel to the main shaft axis. The axial outer end face of the second external tooth is inclined relative to the main shaft axis, and the outer end is farther away from the main shaft axis than the inner end.
[0016] As an improvement, a radial wall and a V-shaped wall are formed on the inner side of the first fixed ring, and an arc-shaped wall is formed on the first moving ring. The radial wall, the arc-shaped wall, and the V-shaped wall form an installation space to accommodate the first sealing ring.
[0017] The first moving ring and the main shaft are interference-fitted.
[0018] As an improvement, both the first and second sealing rings are O-rings.
[0019] As an improvement, the second labyrinth sealing structure is the same as the first labyrinth sealing structure, or the second labyrinth sealing structure differs from the first labyrinth sealing structure only in size.
[0020] As an improvement, the first fixed ring is formed from the first housing.
[0021] As an improvement, the third labyrinth seal structure includes a third sealing ring and multiple third sealing teeth, with the third sealing ring located axially outside the third sealing teeth.
[0022] As an improvement, the third sealing ring includes an axial portion on the outer periphery, a radial portion extending radially inward from the outer end of the axial portion, an inclined portion extending obliquely from the inner side of the outer end of the radial portion, and an end portion extending radially from the inner end of the inclined portion.
[0023] As an improvement, the third sealing tooth axially includes, from the outside to the inside, a first tooth, a first groove, a second tooth, a second groove, a third tooth, a third groove, and a fourth tooth. The axial inner end faces of the first tooth and the fourth tooth are parallel to the main shaft axis, and the end faces of the second tooth and the third tooth are relatively axially inclined, with the outer end being closer to the main shaft axis than the inner end.
[0024] As an improvement, the third sealing tooth is formed by the output shaft sleeve.
[0025] The beneficial effects of this utility model's high waterproof mid-drive motor are that the three rotating connections—between the first housing and the main shaft, between the second housing and the output shaft sleeve, and between the output shaft sleeve and the main shaft—all adopt a labyrinth seal structure, which can reliably ensure a high waterproof seal at the rotating connections. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the high waterproof rating mid-drive motor in Embodiment 1 of this utility model.
[0027] Figure 2 This is a cross-sectional view of the high waterproof rating mid-drive motor of Embodiment 1 of this utility model.
[0028] Figure 3 yes Figure 2 A magnified view of a portion of point A in the middle.
[0029] Figure 4 yes Figure 2 A magnified view of a section at point B.
[0030] Figure 5 yes Figure 2 A magnified view of a section at point C.
[0031] Figure 6 This is a schematic diagram of the structure of the first and second housings of the high waterproof mid-drive motor according to Embodiment 1 of this utility model.
[0032] Figure 7 This is a schematic diagram of the main shaft of the high waterproof-rated mid-drive motor in Embodiment 1 of this utility model.
[0033] Figure 8 This is a schematic diagram of the output shaft sleeve of the high waterproof-level mid-drive motor in Embodiment 1 of this utility model.
[0034] In the figure, 1 is the first housing; 11 is the first sealing tooth; 111 is the first inner groove; 112 is the first inner tooth; 113 is the second inner groove; and 114 is the second inner tooth.
[0035] 2. Second shell;
[0036] 3. Spindle;
[0037] 4. Output shaft sleeve; 41. Third sealing tooth; 411. First tooth; 412. First groove; 413. Second tooth; 414. Second groove; 415. Third tooth; 416. Third groove; 417. Fourth tooth;
[0038] 5. First moving ring; 51. Second sealing tooth; 511. First external tooth; 512. First external groove; 513. Second external tooth; 514. Second external groove; 515. Third external tooth;
[0039] 6. First sealing ring;
[0040] 7. Second sealing ring;
[0041] 8. Third sealing ring; 81. Axial part; 82. Radial part; 83. Inclined part; 84. End part. Detailed Implementation
[0042] The technical solutions of the embodiments of the present invention will be explained and described below. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.
[0043] See Figures 1 to 8 The high waterproof mid-drive motor of this utility model embodiment includes:
[0044] Gear motor body;
[0045] The outer casing includes a first casing and a second casing that are axially distributed;
[0046] The sensor assembly includes a spindle and a torque sensor on the spindle, with the torque sensor located inside the housing and both ends of the spindle located outside the housing.
[0047] The output shaft sleeve is driven by the geared motor body, with one end located inside the housing and the other end located outside the housing;
[0048] The first housing and the main shaft form a first labyrinth seal structure, the second housing and the output shaft sleeve form a second labyrinth seal structure, and the output shaft sleeve and the main shaft form a third labyrinth seal structure.
[0049] This utility model relates to a high-waterproof mid-drive motor. The three rotating connections—between the first housing and the main shaft, between the second housing and the output shaft sleeve, and between the output shaft sleeve and the main shaft—all employ labyrinth seal structures, reliably ensuring a high level of waterproof sealing at these connections. A labyrinth seal is a seal created by numerous tortuous chambers between rotating and stationary parts to reduce leakage. The labyrinth seal has several sequentially arranged annular sealing teeth around the shaft, forming a series of flow-blocking gaps and expansion cavities between the teeth. The sealed medium experiences a throttling effect as it passes through the gaps in the labyrinth, thus preventing leakage.
[0050] Example 1
[0051] See Figures 1 to 8 The high waterproof mid-drive motor of Embodiment 1 of this utility model includes:
[0052] Gear motor body;
[0053] The outer casing includes a first housing 1 and a second housing 2 that are axially distributed.
[0054] The sensor assembly includes a spindle 3 and a torque sensor on the spindle 3. The torque sensor is located in the housing, and both ends of the spindle 3 are located outside the housing.
[0055] The output shaft sleeve 4 is driven by the geared motor body, with one end located inside the housing and the other end located outside the housing;
[0056] The first housing 1 and the main shaft 3 form a first labyrinth seal structure, the second housing 2 and the output shaft sleeve 4 form a second labyrinth seal structure, and the output shaft sleeve 4 and the main shaft 3 form a third labyrinth seal structure.
[0057] In this embodiment, the first labyrinth sealing structure includes a first fixed ring on the first housing 1, a first moving ring 5 on the main shaft 3, a first sealing ring 6 between the first fixed ring and the first moving ring 5, and a second sealing ring 7 between the first moving ring 5 and the main shaft 3. The first sealing ring 6 and the second sealing ring 7 are axially distributed. A first sealing tooth 11 is formed on the inner side of the first fixed ring, and a second sealing tooth 51 is formed on the outer side of the first moving ring 5.
[0058] In this embodiment, the first sealing tooth 11 includes, from the outside to the inside, a first inner groove 111, a first inner tooth 112, a second inner groove 113, and a second inner tooth 114 in axial direction. The radial depth of the first inner groove 111 is greater than that of the second inner groove 113. The end face of the first inner tooth 112 is inclined relative to the axis of the main shaft 3 and the outer end is closer to the axis of the main shaft 3 than the inner end. The axial inner end face of the second inner tooth 114 is parallel to the axis of the main shaft 3.
[0059] The second sealing tooth 51 includes, from the outside to the inside, a first external tooth 511, a first external groove 512, a second external tooth 513, a second external groove 514 and a third external tooth 515. The axial outer end faces of the first external tooth 511 and the third external tooth 515 are parallel to the axis of the main shaft 3. The axial outer end face of the second external tooth 513 is inclined relative to the axis of the main shaft 3 and the outer end is farther away from the axis of the main shaft 3 than the inner end.
[0060] In this embodiment, a radial wall and a V-shaped wall (more precisely, a √-shaped wall of inconsistent lengths) are formed on the inner side of the first fixed ring, and an arc-shaped wall is formed on the first moving ring 5. The radial wall, the arc-shaped wall, and the V-shaped wall form an installation space for accommodating the first sealing ring 6.
[0061] In this embodiment, the first moving ring 5 and the main shaft 3 are interference-fitted. A stepped portion is formed on the main shaft 3, which restricts or positions the first moving ring 5.
[0062] In this embodiment, both the first sealing ring 6 and the second sealing ring 7 are O-rings.
[0063] In this embodiment, the second labyrinth sealing structure and the first labyrinth sealing structure differ only in size.
[0064] In this embodiment, the first fixed ring is formed by the first housing 1, that is, the first fixed ring is directly processed on the first fixed ring.
[0065] In this embodiment, the third labyrinth sealing structure includes a third sealing ring 8 and multiple third sealing teeth, with the third sealing ring 8 located axially outside the third sealing teeth. The third sealing ring 8 is an oil seal.
[0066] In this embodiment, the third sealing ring 8 includes an axial portion 81 on the outer periphery, a radial portion 82 extending radially inward from the outer end of the axial portion 81, an inclined portion 83 extending obliquely from the inner side of the outer end of the radial portion 82, and an end portion 84 extending radially from the inner end of the inclined portion 83.
[0067] In this embodiment, the third sealing tooth 41 includes, from the outside to the inside, a first tooth 411, a first groove 412, a second tooth 413, a second groove 414, a third tooth 415, a third groove 416, and a fourth tooth 417. The inner end faces of the first tooth 411 and the fourth tooth 417 are parallel to the axis of the main shaft 3. The end faces of the second tooth 413 and the third tooth 415 are inclined relative to the axis, and the outer end is closer to the axis of the main shaft 3 than the inner end.
[0068] In this embodiment, the third sealing tooth 41 is formed by the output shaft sleeve 4, that is, the third sealing tooth 41 is directly machined on the output shaft sleeve 4.
[0069] In this embodiment, in assisted riding mode, the pedal drives the main shaft 3 to rotate. The torque sensor detects the torque and transmits it to the controller. The controller controls the geared motor to provide proportional driving torque to the output shaft sleeve 4. In assisted riding mode, the main shaft 3 rotates, and the output shaft sleeve 4 also rotates. In manual riding mode, the main shaft 3 rotates, but the output shaft sleeve 4 does not rotate. In both riding modes, the outer casing does not rotate.
[0070] In this embodiment, the first moving ring 5 is fixed to the main shaft 3 by an interference fit, and an O-ring is provided between the first moving ring 5 and the main shaft 3 to ensure a reliable connection between the first moving ring 5 and the main shaft 3, and also to ensure a seal between the first moving ring 5 and the main shaft 3.
[0071] In this embodiment, when the spindle 3 is stationary or basically stationary, the second sealing ring 7 between the first moving ring 5 and the first fixed ring works in conjunction with the first sealing tooth 11 and the second sealing tooth 51 to achieve double waterproofing.
[0072] In this embodiment, when the rotational speed of the main shaft 3 reaches a certain range, the second sealing ring 7 between the first moving ring 5 and the first fixed ring is tightly attached to the V-shaped wall under the action of centrifugal force, etc., forming a seal at high speed.
[0073] In this embodiment, the oil seal between the output shaft sleeve 4 and the main shaft 3, together with the third sealing tooth 41, ensures that the output shaft sleeve 4 and the main shaft 3 are sealed and waterproof, and the structure is relatively simple and does not require additional sealing materials.
[0074] The beneficial effects of the high waterproof mid-drive motor of Embodiment 1 of this utility model are as follows: the three rotating connections between the first housing 1 and the main shaft 3, the second housing 2 and the output shaft sleeve 4, and the output shaft sleeve 4 and the main shaft 3 all adopt a labyrinth seal structure, which can reliably ensure a high waterproof seal at the rotating connections; the labyrinth seal structure between the first housing 1 and the main shaft 3 is almost the same as that between the second housing 2 and the output shaft sleeve 4, but different from that between the output shaft sleeve 4 and the main shaft 3; it can achieve IPX7 waterproof performance; and the overall structure is compact.
[0075] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the content described in the above specific embodiments. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.
Claims
1. A high waterproof class middle motor, characterized in that: The high-water-resistance mid-drive motor includes: Gear motor body; The outer casing includes a first housing (1) and a second housing (2) distributed axially; The sensor assembly includes a spindle (3) and a torque sensor on the spindle (3), the torque sensor being located inside the housing and both ends of the spindle (3) being located outside the housing; The output shaft sleeve (4) is driven by the geared motor body, with one end located inside the housing and the other end located outside the housing; Among them, a first labyrinth seal structure is formed between the first housing (1) and the main shaft (3), a second labyrinth seal structure is formed between the second housing (2) and the output shaft sleeve (4), and a third labyrinth seal structure is formed between the output shaft sleeve (4) and the main shaft (3).
2. The high waterproof rating middle motor of claim 1, wherein: The first labyrinth sealing structure includes a first fixed ring on the first housing (1), a first moving ring (5) on the main shaft (3), a first sealing ring (6) between the first fixed ring and the first moving ring (5), and a second sealing ring (7) between the first moving ring (5) and the main shaft (3). The first sealing ring (6) and the second sealing ring (7) are axially distributed. A first sealing tooth (11) is formed on the inner side of the first fixed ring, and a second sealing tooth (51) is formed on the outer side of the first moving ring (5).
3. The high waterproofness grade middle-embedded motor according to claim 2, characterized in that: The first sealing tooth (11) includes, from the outside to the inside, a first inner groove (111), a first inner tooth (112), a second inner groove (113), and a second inner tooth (114). The radial depth of the first inner groove (111) is greater than that of the second inner groove (113). The end face of the first inner tooth (112) is inclined relative to the axis of the main shaft (3), and the outer end is closer to the axis of the main shaft (3) than the inner end. The axial inner end face of the second inner tooth (114) is parallel to the axis of the main shaft (3). The second sealing tooth (51) includes, from the outside to the inside, a first external tooth (511), a first external groove (512), a second external tooth (513), a second external groove (514), and a third external tooth (515). The axial outer end faces of the first external tooth (511) and the third external tooth (515) are parallel to the axis of the main shaft (3). The axial outer end face of the second external tooth (513) is inclined relative to the axis of the main shaft (3), and the outer end is farther away from the axis of the main shaft (3) than the inner end.
4. The high waterproofness grade middle-embedded motor according to claim 3, characterized in that: The inner side of the first fixed ring forms a radial wall and a V-shaped wall, and the first moving ring (5) forms an arc-shaped wall. The radial wall, the arc-shaped wall and the V-shaped wall form an installation space to accommodate the first sealing ring (6). The first moving ring (5) and the main shaft (3) are interference-fitted.
5. The high waterproof degree middle-embedded motor according to claim 2, characterized in that: Both the first sealing ring (6) and the second sealing ring (7) are O-rings; the first fixed ring is formed by the first housing (1).
6. High waterproof class medium-embedded motor according to any of claims 1 to 5, characterized in that: The second labyrinth sealing structure is the same as the first labyrinth sealing structure, or the second labyrinth sealing structure differs from the first labyrinth sealing structure only in size.
7. High waterproof class medium-embedded motor according to any of claims 1 to 5, characterized in that: The third labyrinth sealing structure includes a third sealing ring (8) and a third sealing tooth (41), with the third sealing ring (8) located axially outside the third sealing tooth (41).
8. The high waterproof degree middle-embedded motor according to claim 7, characterized in that: The third sealing ring (8) includes an axial portion (81) on the outer periphery, a radial portion (82) extending radially inward from the outer end of the axial portion (81), an inclined portion (83) extending obliquely from the inner side of the outer end of the radial portion (82), and an end portion (84) extending radially from the inner end of the inclined portion (83).
9. The high waterproof degree middle-embedded motor according to claim 7, characterized in that: The third sealing tooth (41) includes, from the outside to the inside, a first tooth (411), a first groove (412), a second tooth (413), a second groove (414), a third tooth (415), a third groove (416), and a fourth tooth (417). The inner end faces of the first tooth (411) and the fourth tooth (417) are parallel to the axis of the main shaft (3). The end faces of the second tooth (413) and the third tooth (415) are inclined relative to the axis, and the outer end is closer to the axis of the main shaft (3) than the inner end.
10. The high waterproof rating middle motor of claim 7, wherein: The third sealing tooth (41) is formed by the output shaft sleeve (4).