Middle motor and electric moped
By using bevel tooth assembly and torque detection structure in the mid-motor, the problems of large volume and inaccurate torque detection of the mid-motor are solved, and the lightweight and precise riding torque detection of the electric moped is realized, which improves the riding experience and service life.
Patent Information
- Application Number
- CN202422419889.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-08
- Publication Date
- 2025-07-11
- Estimated Expiration
- 2034-10-08
AI Technical Summary
The existing mid-mounted motor has a large size and a complex transmission structure, which cannot accurately detect user riding torque, resulting in a complex structure and poor riding experience of electric mopeds.
The transmission structure is formed by bevel teeth assembled, and the torque detection structure is installed on the central shaft, combining the clutch and bevel teeth assembled to realize torque detection and transmission functions, simplify wiring and improve detection accuracy.
It realizes the lightweight design of the mid-mounted motor, accurately detects riding torque, simplifies the routing of electric mopeds, improves the riding experience, and extends the service life.
Smart Images
Figure CN223086217U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of electric power-assisted vehicles, in particular to a mid-mounted motor and an electric power-assisted vehicle Background Art
[0002] At present, electric power-assisted vehicles have become common social means of transportation, with wide application range and high environmental protection value, and have high prospects and development. As the core component of an electric power-assisted vehicle, the power, load-bearing capacity, durability and volume of a mid-mounted motor will directly affect the performance of the electric power-assisted vehicle. Due to the complex characteristics of its transmission structure (usually a planetary gear mechanism), the existing mid-mounted motor has a relatively large volume, which is not conducive to the lightweight design of the electric power-assisted vehicle. And when the existing mid-mounted motor is used in a power-assisted vehicle, it cannot accurately control the operating power of the mid-mounted motor according to the user's riding torque. It is necessary to additionally set a torque detection sensor outside the mid-mounted motor to detect the user's riding torque, which will make the wiring and structure of the power-assisted vehicle complex Summary of the Utility Model
[0003] The first object of the utility model is to provide a mid-mounted motor, which has a small volume and a light weight, is conducive to the lightweight design of an electric power-assisted vehicle, and can relatively accurately detect the user's riding torque
[0004] The second object of the utility model is to provide an electric power-assisted vehicle, which has a light weight, can accurately detect the user's riding torque, simplifies the wiring of the electric power-assisted vehicle, and is conducive to improving the user's riding experience
[0005] To achieve the above technical effects, the technical solution of the utility model is as follows
[0006] The utility model discloses a mid-mounted motor for an electric power-assisted vehicle, comprising: a housing, the housing defining an installation cavity; a central shaft, the central shaft passing through the installation cavity, and both ends of the central shaft being used for connecting with pedals; a motor stator, the motor stator being installed in the installation cavity and fixedly connected with the housing; a motor rotor, the motor rotor being installed in the installation cavity and sleeved on the motor stator; a transmission shaft, the transmission shaft passing through the motor rotor and capable of synchronously rotating with the motor rotor; a bevel gear assembly, the bevel gear assembly comprising a first bevel gear and a second bevel gear meshing with each other, the first bevel gear being connected with the transmission shaft; a clutch, the clutch being connected between the second bevel gear and the central shaft, and a chainring protruding out of the installation cavity being arranged on the clutch; the clutch is used to prevent the central shaft from driving the motor rotor to reverse, and allows the central shaft to rotate idly when the pedal reverses; a torque detection structure, the torque detection structure being installed on the central shaft and used for detecting the torque received by the central shaft
[0007] In some embodiments, the clutch includes: a ratchet outer ring mounted on the second bevel gear and capable of rotating synchronously with the second bevel gear; a clutch body passing through the ratchet outer ring and having a first ratchet tooth cooperating with the ratchet outer ring. A ratchet inner ring is further provided on the clutch body, and the sprocket is provided on the clutch body; a ratchet sleeve sleeved on the central shaft and capable of rotating synchronously with the central shaft, and a second ratchet tooth cooperating with the ratchet inner ring is provided on the outer side wall of the ratchet sleeve.
[0008] In some specific embodiments, a first bearing, a second bearing and a third bearing are provided on the clutch body at intervals along its axial direction. The outer ring of the first bearing abuts against the inner side wall of the installation cavity and is located at one end of the clutch body away from the sprocket; the outer side wall of the second bearing abuts against the inner side wall of the second bevel gear, and the outer ring of the third bearing abuts against the inner side wall of the installation cavity and is located at one end of the clutch body close to the sprocket; a bushing is sleeved on the clutch body, and both ends of the bushing respectively abut against the first bearing and the second bearing.
[0009] In some more specific embodiments, a spline groove is provided on one of the ratchet sleeve and the central shaft, and a spline tooth cooperating with the spline groove is provided on the other of the ratchet sleeve and the central shaft.
[0010] In some more specific embodiments, a fourth bearing and a fifth bearing are respectively provided at both ends of the central shaft. The outer ring of the fourth bearing abuts against the inner side wall of the clutch body; the fifth bearing abuts against the inner side wall of the installation cavity.
[0011] In some embodiments, a partition is provided in the installation cavity to divide the installation cavity into a motor cavity and a central shaft cavity. The central shaft and the clutch are installed in the central shaft cavity, and both ends of the central shaft penetrate through the central shaft cavity. One end of the clutch having the sprocket extends out of the central shaft cavity; the motor stator and the motor rotor are installed in the motor cavity; wherein: the transmission shaft is rotatably passed through the partition, and a first oil seal is provided in the fitting gap between the transmission shaft and the partition.
[0012] In some specific embodiments, a protrusion protruding towards the motor cavity is provided on the partition. The first oil seal is installed on the protrusion, and a sixth bearing is provided between the protrusion and the transmission shaft.
[0013] In some specific embodiments, one end of the central shaft cavity is open, and the other end is provided with a shaft hole for the central shaft to pass through; the mid-mounted motor further includes a second oil seal, a third oil seal and a fourth oil seal; wherein:
[0014] The second oil seal is installed in the space between the inner wall of the middle shaft cavity and the part of the clutch extending out of the middle shaft cavity;
[0015] The third oil seal is installed in the space between the inner wall of one end of the middle shaft cavity with a shaft hole and the outer wall of the clutch;
[0016] The fourth oil seal is installed in the space between the part of the clutch extending out of the middle shaft cavity and one end of the middle shaft far from the chainring.
[0017] In some specific embodiments, one end of the motor cavity is open, and the motor stator and the motor rotor are both installed in the motor cavity;
[0018] The mid-mounted motor further includes a side cover and a gland. The side cover is buckled on the open end of the motor cavity, and one end of the transmission shaft far from the first bevel gear is rotatably supported by the side cover; the gland is installed in the motor cavity and is hermetically connected to the side cover, and one end of the gland facing away from the side cover abuts against the motor stator; wherein:
[0019] A seventh bearing is provided between the side cover and the transmission shaft, and an eighth bearing is provided between the motor stator and the transmission shaft.
[0020] The present utility model also discloses an electric assist vehicle, including a vehicle body and the mid-mounted motor described above. The mid-mounted motor is installed on the vehicle body, and pedals are installed at both ends of the middle shaft of the mid-mounted motor.
[0021] Advantages of the mid-mounted motor of the present utility model: During the user's riding process, when the pedal rotates forward, it can drive the middle shaft to rotate. During the rotation of the middle shaft, the torque detection structure installed on the middle shaft can detect the torque received by the middle shaft. The control system of the electric assist vehicle can control the rotation speed of the motor rotor according to the detection structure, so as to adjust the assistance magnitude provided by the mid-mounted motor to the user. Compared with the prior art in which a torque detection sensor is additionally provided outside the mid-mounted motor to detect the riding torque of the user, in this embodiment, the torque detection structure is installed on the middle shaft. On the one hand, it is convenient for wire routing, and on the other hand, it is convenient to accurately detect the torque received by the middle shaft. When the motor rotor rotates, it can drive the transmission shaft to rotate, so that the first bevel gear drives the second bevel gear to rotate. During the rotation of the second bevel gear, it can drive the middle shaft to rotate. The first bevel gear and the second bevel gear can form a speed reducer, which can increase the output torque and reduce the speed on the one hand, and can improve the load-bearing capacity and durability on the other hand, and perform well in bearing heavy loads and impact loads, which is beneficial to extending the service life of the mid-mounted motor. At the same time, compared with the planetary gear structure in the prior art, the transmission structure composed of the bevel gear assembly has a more compact structure and a smaller weight, which is beneficial to reducing the volume and weight of the mid-mounted motor and is beneficial to the lightweight design of the electric assist vehicle.
[0022] Advantages of the electric assisted vehicle of the present utility model: Due to the mid-mounted motor described above, a torque detection structure is installed on the central shaft of the mid-mounted motor. On the one hand, it is convenient for wire routing, and on the other hand, it is convenient to accurately detect the torque received by the central shaft, so as to accurately detect the riding torque of the user, simplify the wire routing of the electric assisted vehicle, and is beneficial to improving the user's riding experience. At the same time, compared with the planetary gear structure in the prior art, the mid-mounted motor uses a bevel gear assembly to form a transmission structure, and the structure of the bevel gear assembly is more compact and lighter in weight, which is beneficial to reducing the volume and weight of the mid-mounted motor and is beneficial to the lightweight design of the electric assisted vehicle.
[0023] Additional aspects and advantages of the present utility model will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 is a schematic structural diagram of the mid-mounted motor according to an embodiment of the present utility model;
[0025] Figure 2 is a sectional view of the mid-mounted motor according to an embodiment of the present utility model;
[0026] Figure 3 is a schematic structural diagram of the central shaft, ratchet sleeve and torque detection device according to an embodiment of the present utility model;
[0027] Figure 4 is a schematic structural diagram of the clutch and the central shaft according to an embodiment of the present utility model;
[0028] Figure 5 is Figure 4 an exploded schematic diagram of the structure shown;
[0029] Figure 6 is a schematic structural diagram of the motor stator, side cover and gland of the present utility model.
[0030] REFERENCE MARKS:
[0031] 10. Housing; 101. Installation cavity; 1011. Central axis cavity; 1012. Motor cavity; 102. Partition; 1021. Protrusion; 11. Central axis; 111. Spline teeth; 12. Motor stator; 13. Motor rotor; 14. Transmission shaft; 15. Bevel gear assembly; 151. First bevel gear; 152. Second bevel gear; 16. Clutch; 161. Ratchet outer ring; 162. Clutch body; 1621. Sprocket; 1622. First ratchet teeth; 163. Ratchet sleeve; 1631. Second ratchet teeth; 1632. Spline groove; 17. Torque detection structure; 18. First bearing; 19. Second bearing; 20. Third bearing; 21. Fourth bearing; 22. Fifth bearing; 23. First oil seal; 24. Second oil seal; 25. Third oil seal; 26. Fourth oil seal; 27. Side cover; 28. Gland; 29. Seventh bearing; 30. Eighth bearing; 31. Bushing; 32. Sixth bearing. Detailed implementation manners
[0032] The present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. Additionally, it should be noted that for the sake of description, only parts related to the present utility model rather than all structures are shown in the accompanying drawings.
[0033] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0034] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is at a higher horizontal height than the second feature. The first feature being "below", "beneath", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the first feature is at a lower horizontal height than the second feature.
[0035] In the description of this embodiment, the orientation or positional relationships such as "upper", "lower", "right", etc. are based on the orientation or positional relationships shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for differentiation in description and have no special meaning.
[0036] The present utility model discloses a mid-mounted motor, which is used for an electric assist vehicle. Refer to Figure 1 and Figure 2As shown in the figure, the mid-drive motor includes a housing 10, a central shaft 11, a motor stator 12, a motor rotor 13, a transmission shaft 14, a bevel gear assembly 15, a clutch 16, and a torque detection structure 17. The housing 10 defines an installation cavity 101. The central shaft 11 passes through the installation cavity 101, and both ends of the central shaft 11 are used to connect to the pedals. The motor stator 12 is installed in the installation cavity 101 and fixedly connected to the housing 10. The motor rotor 13 is installed in the installation cavity 101 and sleeved on the motor stator 12. The transmission shaft 14 passes through the motor rotor 13 and can rotate synchronously with the motor rotor 13. The bevel gear assembly 15 includes a first bevel gear 151 and a second bevel gear 152 that mesh with each other. The first bevel gear 151 is connected to the transmission shaft 14. The clutch 16 is connected between the second bevel gear 152 and the central shaft 11, and a chainring 1621 that extends out of the installation cavity 101 is provided on the clutch 16. The clutch 16 is used to prevent the central shaft 11 from driving the motor rotor 13 to reverse, and allows the central shaft 11 to rotate idly when the pedal reverses. The torque detection structure 17 is installed on the central shaft 11 and is used to detect the torque received by the central shaft 11. It can be understood that during the user's cycling process, when the pedal rotates forward, it can drive the central shaft 11 to rotate. During the rotation of the central shaft 11, the torque detection structure 17 installed on the central shaft 11 can detect the torque received by the central shaft 11. The control system of the electric assist vehicle can control the rotation speed of the motor rotor 13 according to the torque detection structure 17, so as to adjust the assist force provided by the mid-drive motor to the user. Compared with the prior art in which a torque detection sensor is additionally provided outside the mid-drive motor to detect the user's cycling torque, in this embodiment, the torque detection structure 17 is installed on the central shaft 11. On the one hand, it is convenient for wiring, and on the other hand, it is convenient to accurately detect the torque received by the central shaft 11. When the motor rotor 13 rotates, it can drive the transmission shaft 14 to rotate, so that the first bevel gear 151 drives the second bevel gear 152 to rotate. During the rotation of the second bevel gear 152, it can drive the central shaft 11 to rotate. The first bevel gear 151 and the second bevel gear 152 can form a speed reducer, which can increase the output torque and reduce the speed on the one hand, and can improve the load-bearing capacity and durability on the other hand, and perform well in withstanding heavy loads and impact loads, which is beneficial to extending the service life of the mid-drive motor. At the same time, compared with the planetary gear structure in the prior art, the bevel gear assembly 15 is used to form the transmission structure. The structure of the bevel gear assembly 15 is more compact and lighter in weight, which is beneficial to reducing the volume and weight of the mid-drive motor and is beneficial to the lightweight design of the electric assist vehicle.
[0037] Optionally, the torque detection structure 17 can be a torque deformation sleeve or a sensor structure such as a strain gauge. The specific type of the torque detection structure 17 can be selected according to actual needs.
[0038] Reference Figure 3 and Figure 4As shown, the clutch 16 includes a ratchet outer ring 161, a clutch body 162, and a ratchet sleeve 163. The ratchet outer ring 161 is mounted on the second bevel gear 152 and can rotate synchronously with the second bevel gear 152. The clutch body 162 is passed through the ratchet outer ring 161 and has a first ratchet tooth 1622 that cooperates with the ratchet outer ring 161. A ratchet inner ring is also provided on the clutch body 162, and a chainring 1621 is provided on the clutch body 162. The ratchet sleeve 163 is sleeved on the central shaft 11 and can rotate synchronously with the central shaft 11. The outer side wall of the ratchet sleeve 163 has a second ratchet tooth 1631 that cooperates with the ratchet inner ring. It can be understood that during the user's riding process, when the user drives the foot pedal to make the central shaft 11 rotate forward, the second ratchet tooth 1631 locks with the ratchet inner ring, and the central shaft 11 can drive the clutch body 162 to rotate, so that the chainring 1621 rotates, thereby making the wheels of the electric assisted vehicle rotate forward, so that the electric assisted vehicle moves forward. During the forward movement, if the motor rotor 13 receives a signal to rotate forward, the second bevel gear 152 drives the ratchet outer ring 161 to also rotate forward. At this time, the ratchet outer ring 161 locks with the first ratchet tooth 1622, and the ratchet outer ring 161 can drive the clutch body 162 to rotate, thereby enabling the motor rotor 13 to assist the central shaft 11 to rotate. If the motor rotor 13 fails and rotates in reverse, due to the one-way transmission function of the ratchet outer ring 161 and the first ratchet tooth 1622, the reverse rotating motor rotor 13 cannot drive the clutch body 162 to rotate in reverse, thereby avoiding the riding resistance caused by the motor reversing. If during the forward rotation of the motor rotor 13, the foot pedal drives the central shaft 11 to rotate in reverse, due to the one-way transmission function of the second ratchet tooth 1631 and the ratchet inner ring, the reverse rotation of the central shaft 11 will not drive the clutch body 162 to rotate in reverse. At this time, the central shaft 11 is in an idling state, avoiding the riding resistance caused by the reverse rotation of the pedal. In addition, when pushing the electric assisted vehicle to reverse, the chainring 1621 will rotate in reverse, thereby causing the clutch body 162 to rotate in reverse. The reverse rotating clutch body 162 can neither drive the central shaft 11 to rotate in reverse nor drive the motor rotor 13 to rotate in reverse, ensuring the safety of reversing.
[0039] Optionally, the torque detection structure 17 is sleeved on the ratchet sleeve 163. According to the above-mentioned ratchet sleeve 163 and the central shaft 11 being an integral rotation structure, sleeving the torque detection structure 17 on the ratchet sleeve 163 can not only facilitate the measurement of the torque received by the central shaft 11, but also eliminate the need to specifically reserve space for installing the torque detection structure 17 on the central shaft 11, which is beneficial to shortening the length of the central shaft 11.
[0040] Reference Figure 2As shown, a partition 102 is provided in the installation cavity 101 to divide the installation cavity 101 into a motor cavity 1012 and a central shaft cavity 1011. The central shaft 11 and the clutch 16 are installed in the central shaft cavity 1011. Both ends of the central shaft 11 extend out of the central shaft cavity 1011. One end of the clutch 16 with a chainring 1621 extends out of the central shaft cavity 1011; the motor stator 12 and the motor rotor 13 are installed in the motor cavity 1012; wherein: the transmission shaft 14 is rotatably disposed through the partition 102, and a first oil seal 23 is provided in the fitting gap between the transmission shaft 14 and the partition 102. It can be understood that during the actual manufacturing process, the motor stator 12 usually needs to be fixed by potting. In this embodiment, by providing the partition 102 to divide the installation cavity 101 into the motor cavity 1012 and the central shaft cavity 1011, and separating the motor cavity 1012 and the central shaft cavity 1011 by the first oil seal 23, the phenomenon that glue enters the central shaft cavity 1011 when the motor stator 12 is fixed by potting is avoided.
[0041] Optionally, referring to Figure 2 As shown, the partition 102 is provided with a protruding portion 1021 protruding towards the motor cavity 1012. The first oil seal 23 is installed on the protruding portion 1021, and a sixth bearing 32 is provided between the protruding portion 1021 and the transmission shaft 14. It can be understood that the protruding portion 1021 is provided to install the first oil seal 23, which can ensure that the first oil seal 23 completely separates the motor cavity 1012 and the central shaft cavity 1011, avoiding the phenomenon that glue enters the central shaft cavity 1011 when the motor stator 12 is fixed by potting. On the one hand, the sixth bearing 32 plays a role in supporting the transmission shaft 14, and on the other hand, it reduces the friction between the transmission shaft 14 and the partition 102, thereby reducing the wear of the transmission shaft 14.
[0042] Referring to Figure 2As shown in the figure, the clutch body 162 is provided with a first bearing 18, a second bearing 19, and a third bearing 20 that are axially spaced along it. The outer ring of the first bearing 18 abuts against the inner wall of the middle shaft cavity 1011 and is located at one end of the clutch body 162 away from the chainring 1621; the outer side wall of the second bearing 19 abuts against the inner wall of the second bevel gear 152, and the outer ring of the third bearing 20 abuts against the inner wall of the installation cavity 101 and is located at one end of the clutch body 162 close to the chainring 1621; a bushing 31 is sleeved on the clutch body 162, and both ends of the bushing 31 respectively abut against the first bearing 18 and the second bearing 19. It can be understood that through the stable support of the first bearing 18, the second bearing 19, and the third bearing 20, the clutch body 162 can rotate stably during actual operation. The first bearing 18 reduces the friction between the clutch body 162 and the inner wall of the middle shaft cavity 1011, the second bearing 19 reduces the friction between the clutch body 162 and the second bevel gear 152 when the clutch body 162 rotates in reverse, and the third bearing 20 reduces the friction between the clutch body 162 and the inner wall of the middle shaft cavity 1011. The first bearing 18, the second bearing 19, and the third bearing 20 reduce the possible wear of the clutch body 162 during actual operation, which is beneficial to extending the working life of the mid-mounted motor.
[0043] Reference Figure 5 As shown in the figure, the ratchet sleeve 163 is provided with a spline groove 1632, and the middle shaft 11 is provided with spline teeth 111 that cooperate with the spline groove 1632. It can be understood that through the cooperation of the spline groove 1632 and the spline teeth 111, the connection stability between the middle shaft 11 and the ratchet sleeve 163 can be improved, avoiding relative rotation between the two, so as to ensure the stable operation of the mid-mounted motor. Of course, in an alternative embodiment, the ratchet sleeve 163 is provided with spline teeth 111, and the middle shaft 11 is provided with a spline groove 1632. In addition, in other embodiments of the present invention, the ratchet sleeve 163 and the middle shaft 11 can also be connected through connection structures such as fixing pins, interference fits, and flat keys, which are not limited to the above description.
[0044] Reference Figure 2 As shown in the figure, the two ends of the middle shaft 11 are respectively provided with a fourth bearing 21 and a fifth bearing 22. The outer ring of the fourth bearing 21 abuts against the inner wall of the clutch body 162; the fifth bearing 22 abuts against the inner wall of the middle shaft cavity 1011. It can be understood that through the stable support of the fourth bearing 21 and the fifth bearing 22, the middle shaft 11 can rotate stably during actual operation. The fourth bearing 21 can reduce the friction of the middle shaft 11 relative to the clutch body 162 when the middle shaft 11 rotates in reverse, and the fifth bearing 22 can reduce the friction between the middle shaft 11 and the inner wall of the middle shaft cavity 1011. The fourth bearing 21 and the fifth bearing 22 reduce the possible wear of the middle shaft 11 during actual operation, which is beneficial to extending the working life of the mid-mounted motor.
[0045] Reference Figure 2 As shown, one end of the central axis cavity 1011 is open, and the other end is provided with a shaft hole for the central axis 11 to pass through; the mid-mounted motor further includes a second oil seal 24, a third oil seal 25 and a fourth oil seal 26. The second oil seal 24 is installed in the space between the inner side wall of the central axis cavity 1011 and the part of the clutch 16 extending out of the central axis cavity 1011; the third oil seal 25 is installed in the space between the inner side wall of the end of the central axis cavity 1011 with the shaft hole and the outer side wall of the clutch 16; the fourth oil seal 26 is installed in the space between the part of the clutch 16 extending out of the central axis cavity 1011 and the end of the central axis 11 away from the chainring 1621. It can be understood that the second oil seal 24, the third oil seal 25 and the fourth oil seal 26 can, on the one hand, prevent leakage. The above-mentioned oil seals limit and prevent the lubricant from leaking out of the mating gap through the close contact between their lips and the central axis 11 or the clutch body 162, ensuring that the mechanical components in the central axis cavity 1011 are fully lubricated; on the other hand, they have the function of preventing dust and dirt. The oil seals are usually designed with dust lips or secondary lips, which can block external impurities such as dust, dirt and moisture from entering the central axis cavity 1011, protect the precision components from contamination, and extend the service life of the mid-mounted motor.
[0046] It should be added that the parameters of the second oil seal 24, the third oil seal 25 and the fourth oil seal 26 can be selected according to actual needs, and no specific limitations are made on the second oil seal 24, the third oil seal 25 and the fourth oil seal 26 here.
[0047] Reference Figure 2 and Figure 6 As shown, one end of the motor cavity 1012 is open, and the motor stator 12 and the motor rotor 13 are both installed in the motor cavity 1012; the mid-mounted motor further includes a side cover 27 and a gland 28. The side cover 27 is buckled on the open end of the motor cavity 1012, and the end of the transmission shaft 14 away from the first bevel gear 151 is rotatably supported on the side cover 27; the gland 28 is installed in the motor cavity 1012 and is hermetically connected to the side cover 27, and the end of the gland 28 facing away from the side cover 27 abuts against the motor stator 12. It can be understood that the side cover 27, the gland 28 and the motor stator 12 together form a potting structure, which can ensure the fixing stability of the motor stator 12 and avoid the glue overflow during the potting process.
[0048] Optionally, a seventh bearing 29 is provided between the side cover 27 and the transmission shaft 14, and an eighth bearing 30 is provided between the motor stator 12 and the transmission shaft 14. The stable support of the transmission shaft 14 by the seventh bearing 29 and the eighth bearing 30 ensures that the transmission shaft 14 can rotate stably during actual operation. The seventh bearing 29 can reduce the friction between the transmission shaft 14 and the side cover 27, and the eighth bearing 30 can reduce the friction between the transmission shaft 14 and the motor stator 12. The seventh bearing 29 and the eighth bearing 30 reduce the possible wear of the transmission shaft 14 during actual operation, which is beneficial to extending the working life of the mid-mounted motor.
[0049] It should be noted that in this embodiment, the types and sizes of the first bearing 18, the second bearing 19, the sixth bearing 32, the third bearing 20, the fourth bearing 21, the fifth bearing 22, the seventh bearing 29, and the eighth bearing 30 can all be selected according to actual needs, and no description will be made here.
[0050] The present utility model also discloses an electric assist vehicle, including a vehicle body and the aforementioned mid-mounted motor. The mid-mounted motor is installed on the vehicle body, and pedals are installed at both ends of the central shaft 11 of the mid-mounted motor. Due to the aforementioned mid-mounted motor, a torque detection structure 17 is installed on the central shaft 11 of the mid-mounted motor. On the one hand, it is convenient for wire routing, and on the other hand, it is convenient to accurately detect the torque received by the central shaft 11, so as to accurately detect the riding torque of the user, simplify the wire routing of the electric assist vehicle, and is beneficial to improving the user's riding experience. At the same time, compared with the planetary gear structure in the prior art, the transmission structure of the mid-mounted motor using the bevel gear assembly 15 has a more compact structure and a smaller weight, which is beneficial to reducing the volume and weight of the mid-mounted motor and is beneficial to the lightweight design of the electric assist vehicle.
[0051] In the description of this specification, the descriptions referring to terms "some embodiments", "other embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.
[0052] Obviously, the above embodiments of the present utility model are merely examples given to clearly illustrate the present utility model, and are not limitations on the implementation manners of the present utility model. For those of ordinary skill in the art, various obvious changes, re-adjustments and substitutions can be made without departing from the protection scope of the present utility model. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present utility model shall be included in the protection scope of the claims of the present utility model.
Claims
1. A mid-mounted motor for an electric assist vehicle, characterized in that, Comprising: A housing (10), the housing (10) defining an installation cavity (101); A central shaft (11), the central shaft (11) passing through the installation cavity (101), and both ends of the central shaft (11) being used for connection with pedals; A motor stator (12), the motor stator (12) being installed in the installation cavity (101) and fixedly connected to the housing (10); A motor rotor (13), the motor rotor (13) being installed in the installation cavity (101) and sleeved on the motor stator (12); A transmission shaft (14), the transmission shaft (14) passing through the motor rotor (13) and being capable of synchronous rotation with the motor rotor (13); A bevel gear assembly (15), the bevel gear assembly (15) including a first bevel gear (151) and a second bevel gear (152) that mesh with each other, the first bevel gear (151) being connected to the transmission shaft (14); A clutch (16), the clutch (16) being connected between the second bevel gear (152) and the central shaft (11), and a chainring (1621) extending out of the installation cavity (101) being provided on the clutch (16); the clutch (16) is used to prevent the central shaft (11) from driving the motor rotor (13) to reverse, and allows the central shaft (11) to rotate idly when the pedals reverse; A torque detection structure (17), the torque detection structure (17) being installed on the central shaft (11) and used for detecting the torque received by the central shaft (11).
2. The mid-mounted motor according to claim 1, characterized in that, The clutch (16) includes: A ratchet outer ring (161), the ratchet outer ring (161) being installed on the second bevel gear (152) and capable of synchronous rotation with the second bevel gear (152); A clutch body (162), the clutch body (162) passing through the ratchet outer ring (161) and having a first ratchet tooth (1622) that cooperates with the ratchet outer ring (161), a ratchet inner ring is further provided on the clutch body (162), and the chainring (1621) is provided on the clutch body (162); A ratchet sleeve (163), the ratchet sleeve (163) being sleeved on the central shaft (11) and capable of synchronous rotation with the central shaft (11), and a second ratchet tooth (1631) that cooperates with the ratchet inner ring is provided on the outer sidewall of the ratchet sleeve (163).
3. The mid-mounted motor according to claim 2, wherein, The clutch body (162) is provided with a first bearing (18), a second bearing (19) and a third bearing (20) which are arranged at intervals along its axial direction. The outer ring of the first bearing (18) abuts against the inner side wall of the installation cavity (101) and is located at one end of the clutch body (162) away from the chainring (1621); the outer side wall of the second bearing (19) abuts against the inner side wall of the second bevel gear (152), and the outer ring of the third bearing (20) abuts against the inner side wall of the installation cavity (101) and is located at one end of the clutch body (162) close to the chainring (1621); a bushing (31) is sleeved on the clutch body (162), and both ends of the bushing (31) abut against the first bearing (18) and the second bearing (19) respectively.
4. The mid-mounted motor according to claim 3, characterized in that, A spline groove (1632) is provided on one of the ratchet sleeve (163) and the central shaft (11), and a spline tooth (111) matching with the spline groove (1632) is provided on the other of the ratchet sleeve (163) and the central shaft (11).
5. The mid-mounted motor according to claim 3, characterized in that, Both ends of the central shaft (11) are respectively provided with a fourth bearing (21) and a fifth bearing (22). The outer ring of the fourth bearing (21) abuts against the inner side wall of the clutch body (162); the fifth bearing (22) abuts against the inner side wall of the installation cavity (101).
6. The mid-mounted motor according to any one of claims 1-5, characterized in that, A partition plate (102) is provided in the installation cavity (101) to divide the installation cavity (101) into a motor cavity (1012) and a central shaft cavity (1011). The central shaft (11) and the clutch (16) are installed in the central shaft cavity (1011). Both ends of the central shaft (11) penetrate out of the central shaft cavity (1011). One end of the clutch (16) with the chainring (1621) extends out of the central shaft cavity (1011); the motor stator (12) and the motor rotor (13) are installed in the motor cavity (1012); where: The transmission shaft (14) is rotatably penetrated through the partition plate (102), and a first oil seal (23) is provided in the fitting gap between the transmission shaft (14) and the partition plate (102).
7. The mid-mounted motor according to claim 6, wherein, The partition plate (102) is provided with a protruding portion (1021) protruding towards the motor cavity (1012). The first oil seal (23) is installed on the protruding portion (1021), and a sixth bearing (32) is provided between the protruding portion (1021) and the transmission shaft (14).
8. The mid-mounted motor according to claim 6, wherein One end of the central shaft cavity (1011) is open, and the other end is provided with a shaft hole for the central shaft (11) to pass through; the mid-mounted motor further includes a second oil seal (24), a third oil seal (25) and a fourth oil seal (26); where: The second oil seal (24) is installed in the space between the inner side wall of the central shaft cavity (1011) and the part of the clutch (16) extending out of the central shaft cavity (1011). The third oil seal (25) is installed in the space between the inner side wall of one end of the central shaft cavity (1011) with the shaft hole and the outer side wall of the clutch (16). The fourth oil seal (26) is installed in the space between the part of the clutch (16) extending out of the middle shaft cavity (1011) and one end of the middle shaft (11) away from the chainring (1621).
9. The mid-mounted motor according to claim 6, wherein, One end of the motor cavity (1012) is open, and both the motor stator (12) and the motor rotor (13) are installed in the motor cavity (1012); The mid-mounted motor further includes a side cover (27) and a gland (28). The side cover (27) is buckled on the open end of the motor cavity (1012), and one end of the transmission shaft (14) away from the first bevel gear (151) is rotatably supported on the side cover (27); the gland (28) is installed in the motor cavity (1012) and is hermetically connected to the side cover (27), and one end of the gland (28) facing away from the side cover (27) abuts against the motor stator (12); wherein: A seventh bearing (29) is provided between the side cover (27) and the transmission shaft (14), and an eighth bearing (30) is provided between the motor stator (12) and the transmission shaft (14).
10. An electric assisted vehicle, characterized in that, It includes a vehicle body and the mid-mounted motor according to any one of claims 1-9. The mid-mounted motor is installed on the vehicle body, and pedals are installed at both ends of the middle shaft (11) of the mid-mounted motor.