Middle motor with torque detection function

Abstract

The invention relates to the technical field of middle motors, and discloses a middle motor with a torque detection function, the middle motor comprises a motor shell, a middle shaft, a motor assembly, a torque detection sensor and a speed reduction assembly, the middle shaft penetrates through the motor shell and is rotatably connected to the motor shell, the motor assembly is located in the motor shell and coaxially sleeves the middle shaft, and the torque detection sensor is rotatably connected to the motor shell. The torque detection sensor is located between the motor assembly and the middle shaft and electrically connected to a controller of the electric moped, the middle shaft comprises a supporting part, a transmission part and a positioning part which are coaxially arranged, the torque detection sensor is slidably arranged on the supporting part in a sleeving mode, and a first limiting piece is arranged between the torque detection sensor and the supporting part; the transmission part coaxially sleeves the end portion of the torque detection sensor in a sliding mode, a second limiting piece is arranged between the transmission part and the torque detection sensor, the positioning part coaxially penetrates through the transmission part in a sliding mode, and the torque detection sensor abuts against the end wall of the supporting part by pushing the transmission part. The method has the effect of improving the assembly precision of the torque detection function sensor.

Description

Technical Field

[0001] This application relates to the technical field of mid-drive motors, and particularly to a mid-drive motor with a torque detection function. Background Art

[0002] In recent years, the technology of electric assist bicycles has developed rapidly. As the core power component, the mid-drive motor has gradually become the market mainstream due to its advantages such as compact structure and direct power output. The optimization of its performance has always been the focus of the industry. With the continuous improvement of consumers' requirements for riding experience, mid-drive motors with accurate torque detection functions are increasingly in demand in the market.

[0003] When designing existing mid-drive motors, the space layout is extremely compact. Limited by the frame structure of electric vehicles and the pursuit of miniaturization and lightweight of mid-drive motors, the space left for additional functional components inside the motor is very limited.

[0004] Traditional torque detection function sensors often face many problems during installation. On the one hand, their large volume makes it difficult to adapt to the narrow space inside the mid-drive motor, resulting in extremely difficult installation in the limited space, and large-scale redesign and transformation of the internal structure of the motor are required, which undoubtedly greatly increases the R & D cost and production cycle. On the other hand, the existing sensor installation methods are cumbersome, usually requiring complex positioning and fixing steps, and the assembly process may also involve precise debugging of multiple components. This not only reduces production efficiency but also easily causes problems such as sensor failure or decreased detection accuracy due to improper operation during the assembly process. Summary of the Invention

[0005] In order to improve the assembly accuracy of the torque detection function sensor, this application provides a mid-drive motor with a torque detection function.

[0006] The mid-drive motor with a torque detection function provided by this application adopts the following technical solutions: A mid-drive motor with a torque detection function includes a motor housing, a central shaft, a motor assembly, a torque detection sensor, and a reduction assembly. The central shaft passes through the motor housing and is rotatably connected to the motor housing. The motor assembly is located inside the motor housing and is coaxially sleeved on the central shaft. The torque detection sensor is located between the motor assembly and the central shaft and is electrically connected to the controller of the electric assist bicycle. The central shaft includes a support portion, a transmission portion, and a positioning portion arranged coaxially. The torque detection sensor is slidably sleeved on the support portion, and a first limiting member for circumferential limitation is provided between the torque detection sensor and the support portion. The transmission portion is coaxially slidably sleeved on the end of the torque detection sensor, and a second limiting member for circumferential limitation is provided between the transmission portion and the torque detection sensor. The positioning portion coaxially slidably passes through the transmission portion, and the torque detection sensor is pressed against the end wall of the support portion by pushing the transmission portion.

[0007] By adopting the above technical solution, during the assembly process of the torque detection sensor, first, it is slidably sleeved on the support portion of the central shaft and axially positioned by the first limiting member; then, the transmission portion is slidably sleeved on the end of the torque detection sensor and further axially fixed by means of the second limiting member; finally, the positioning portion penetrates through the transmission portion and pushes against the transmission portion, precisely pressing the torque detection sensor against the end wall of the support portion. The entire assembly process enables the torque detection sensor to achieve high-precision installation in a narrow space without complex debugging, effectively improving the assembly efficiency and reliability, and at the same time reducing the problem of decreased detection accuracy caused by improper operation.

[0008] Optionally, the first limiting member includes a first external spline provided on the end of the support portion in a ring shape and a first internal spline provided on one end wall of the torque detection sensor. The torque detection sensor is slidably sleeved on the support portion through the insertion and connection between the first internal spline and the first external spline. The second limiting member includes a second external spline coaxially provided on the other end wall of the torque detection sensor and a second internal spline provided on one end wall of the transmission portion. The transmission portion is slidably sleeved on the torque detection sensor through the insertion and connection between the second internal spline and the second external spline and presses the torque detection sensor against the end wall of the support portion away from the positioning portion.

[0009] By adopting the above technical solution, the connection method between the torque detection sensor, the support portion, and the transmission portion is optimized, and circumferential limiting is achieved by using the spline structure, effectively reducing the possibility of rotational offset of the sensor during the installation process. At the same time, the design of this insertion and connection simplifies the assembly process, improves the assembly efficiency, reduces the assembly error caused by improper operation, thereby improving the accuracy and stability of torque detection. And there is no need to additionally add complex components, which helps to reduce the space occupied by the overall structure and meet the design requirements of miniaturization and lightweight of the mid-mounted motor.

[0010] Optionally, one end of the support portion facing the positioning portion is provided with a plug connector with external splines. The positioning portion is sleeved on the plug connector, and internal splines are provided on its inner wall to cooperate with the external splines of the plug connector. The positioning portion and the plug connector are axially inserted and connected, and a connecting bolt is inserted through the positioning portion. The connecting bolt slidably penetrates through the positioning portion and is rotationally connected to the plug connector by threads.

[0011] By adopting the above technical solution, the axial insertion and connection between the plug connector and the positioning portion can achieve rapid assembly, and at the same time, circumferential limiting is achieved through the insertion and connection between the external splines and the internal splines, effectively improving the assembly accuracy and stability. Using the connecting bolt to connect the support portion and the positioning portion simplifies the operation steps and reduces the risk of loosening caused by vibration or impact during use, thereby improving the detection accuracy of the torque detection sensor.

[0012] Optionally, the motor assembly includes a motor stator, a motor rotor, an induction magnetic ring and a magnetic induction encoder, the motor rotor is mounted on the inner wall of the motor housing, the motor rotor is located at the inner ring of the motor stator and is rotatably connected to the inner wall of the motor housing through a bearing, the induction magnetic ring is coaxially arranged on the end wall of the motor rotor, and the magnetic induction encoder is arranged on the inner wall of the motor housing and is coaxially arranged relative to the induction magnetic ring.

[0013] By adopting the above technical solution, the induction magnetic ring rotates synchronously with the motor rotor, and the magnetic induction encoder determines the specific position and rotation speed of the motor rotor by sensing the magnetic field changes of the induction magnetic ring. This design not only improves the accuracy of motor operation status monitoring, but also provides reliable data support for the control system of the electric power-assisted vehicle, thereby optimizing the power-assisted effect and energy utilization efficiency of the entire vehicle.

[0014] Optionally, the output end of the motor assembly is transmission-connected to the power input end of the reduction assembly, and the output end of the reduction assembly is connected to an output member, which is connected to the central shaft through a clutch, and one end of the output member extending out of the motor housing is connected to the sprocket of the electric power-assisted vehicle, and the reduction assembly includes a sun gear, a planetary gear, a planetary carrier and an inner gear ring, and the sun gear and the planetary carrier are both rotatably sleeved on the transmission part, the sun gear is coaxially connected to the end wall of the motor rotor, the planetary gear is meshed with the sun gear and rotatably set on the planetary carrier, the inner gear ring is set on the inner wall of the motor housing and meshingly sleeved on the planetary gear, and the output member is connected to the planetary carrier through a clutch.

[0015] By adopting the above technical solution, the sun gear is first coaxially connected to the end wall of the motor rotor, and then the planetary gear is synchronously rotated and meshed with the sun gear and the inner gear ring, and the planetary gear is ensured to be rotationally connected to the planetary carrier, and finally the output member is connected to the planetary carrier through the clutch. This arrangement can ensure the assembly accuracy of the reduction component, and at the same time, utilize the transmission characteristics of the planetary gear system to achieve effective deceleration and torque increase of the motor output power, thereby improving the overall transmission efficiency and torque output capacity of the mid-mounted motor.

[0016] Optionally, the reduction assembly is distributed in a plurality of groups along the axial direction of the central axis in the motor housing, and between two adjacent groups of reduction assemblies, adjacent sun gears are connected to the planet carriers of an adjacent group.

[0017] By adopting the above technical solutions, the design of distributing multiple sets of reduction components along the axial direction of the central axis can effectively improve the power transmission efficiency and torque output ability of the mid-mounted motor. The connection method between the sun gear and the planet carrier of adjacent two sets of reduction components not only realizes the step-by-step transmission of power, but also optimizes the spatial layout, making the overall structure more compact. While ensuring efficient power transmission, this design reduces the mutual interference between components, improves the stability and reliability of the system, and provides stronger and smoother power support for the electric assist vehicle.

[0018] Optionally, a heat dissipation mechanism for dissipating heat from the torque detection sensor is provided inside the motor housing. The heat dissipation mechanism includes a heat transfer ring, a cooling ring and a temperature sensor. The cooling ring is fixed on the inner wall of the motor housing. The heat transfer ring is rotatably connected to the inner ring of the cooling ring facing the torque detection sensor. The end wall of the torque detection sensor facing the heat transfer ring is a thermosensitive part, and a connecting block is provided on the outer side wall of its outer ring. A plugging groove is recessed on the heat transfer ring, and the connecting block is in plugging fit with the plugging groove.

[0019] By adopting the above technical solutions, the thermosensitive part of the torque detection sensor can be closely attached to the heat transfer ring, and the heat transfer ring is rotatably connected to the cooling ring fixed on the inner wall of the motor housing. This structural design enables the heat generated by the torque detection sensor to be quickly conducted to the cooling ring, thereby effectively controlling the working temperature of the sensor. At the same time, the real-time monitoring function of the temperature sensor can accurately feedback the temperature change inside the motor. Combined with the function of the cooling ring, it further improves the stability of the torque detection sensor under different working conditions, reduces the decrease in detection accuracy caused by temperature fluctuations, and prolongs the service life of the torque detection sensor.

[0020] Optionally, the inner cavity of the cooling ring is filled with a cooling liquid. A circulating cooling pump electrically connected to the temperature sensor is provided on the outer wall of the motor housing. A partition plate is provided inside the cooling ring. On both sides of the partition plate on the cooling ring, a liquid passing pipe is respectively communicated with the inner cavity. The pipe ends of the two liquid passing pipes penetrate through the motor housing and are respectively connected to the inlet and outlet ends of the circulating cooling pump.

[0021] By adopting the above technical solutions, the setting of the partition plate enables the cooling liquid to form an orderly flow path inside the cooling ring. When the temperature inside the motor housing is too high, under the monitoring of the temperature sensor and with the driving effect of the circulating cooling pump, the flow rate of the cooling liquid can be effectively controlled, so as to quickly take away the heat absorbed by the cooling ring. This design not only keeps the torque detection sensor always within a suitable working temperature range, reduces the possibility of performance degradation caused by overheating, but also significantly improves the heat dissipation efficiency, helps to prolong the service life of the sensor and maintain the stability of the detection accuracy.

[0022] Optionally, a plurality of mounting grooves are provided on the cooling ring, and a heat pipe is inserted into each mounting groove. The heating end of the heat pipe is inserted into the mounting groove and adhesively bonded to the cooling ring through thermal conductive adhesive. The condensation end of the heat pipe penetrates through the motor housing, and a sealing ring is sleeved at the connection between the heat pipe and the motor housing.

[0023] By adopting the above technical solution, when the motor is operating normally, the heating end of the heat pipe is tightly connected to the cooling ring, and can quickly transfer the heat in the cooling ring to the condensation end located outside the motor housing and dissipate it into the external environment. The temperature around the torque detection sensor is effectively controlled, so that it is always within a suitable working temperature range under normal conditions, and the dependence on the circulating cooling pump is also reduced, thereby saving electric power resources. At the same time, the stable temperature environment significantly improves the detection accuracy and working stability of the torque detection sensor, and effectively extends its service life.

[0024] Optionally, a protective net cover is sleeved on the condensation end of each heat pipe extending out of the motor housing, and the protective net cover is connected to the motor housing.

[0025] By adopting the above technical solution, the protective net cover can effectively protect the condensation end of the heat pipe, reduce the damage caused by accidental collision or friction in the external environment, thereby reducing the risk of heat pipe breakage and improving the operation stability of the heat dissipation system.

[0026] In summary, the present application includes at least one of the following beneficial technical effects: 1. During the assembly process of the torque detection sensor, first, it is slidably sleeved on the support portion of the central axis and circumferentially positioned by the first limiting member; then the transmission portion is slidably sleeved on the end of the torque detection sensor, and further circumferentially fixed by means of the second limiting member; finally, the positioning portion penetrates through the transmission portion and pushes against the transmission portion to accurately press the torque detection sensor against the end wall of the support portion. The entire assembly process can achieve high-precision installation of the torque detection sensor in a narrow space without complex debugging, effectively improving the assembly efficiency and reliability, and at the same time reducing the problem of decreased detection accuracy caused by improper operation; 2. The connection method between the torque detection sensor and the support portion and the transmission portion is optimized, and the circumferential limit is realized by using the spline structure, effectively reducing the possibility of rotational offset of the sensor during the installation process. At the same time, this design of plug-in fit simplifies the assembly process, improves the assembly efficiency, reduces the assembly error caused by improper operation, thereby improving the accuracy and stability of torque detection. And there is no need to additionally add complex components, which helps to reduce the space occupation of the overall structure and meet the design requirements of miniaturization and lightweight of the in-wheel motor. 3. The axial plug-in fit between the plug connector and the positioning part enables rapid assembly. At the same time, the circumferential limit is achieved through the plug-in fit between the external and internal flutes, effectively improving the assembly accuracy and stability. The support part and the positioning part are connected by connecting bolts, simplifying the operation steps and reducing the risk of loosening caused by vibration or impact during use, thereby improving the detection accuracy of the torque detection sensor. Description of the Drawings

[0027] Figure 1 is the overall structural schematic diagram of Embodiment 1 of the present application.

[0028] Figure 2 is the sectional view showing the internal structure of the motor housing in Embodiment 1 of the present application.

[0029] Figure 3 is the exploded view showing the connection relationship between the torque detection sensor, the support part, the transmission part and the positioning part in Embodiment 1 of the present application.

[0030] Figure 4 is the overall structural schematic diagram of Embodiment 2 of the present application.

[0031] Figure 5 is the overall structural sectional view of Embodiment 2 of the present application.

[0032] Figure 6 is Figure 5 the enlarged view of part A in

[0033] Figure 7 is the schematic diagram showing the connection relationship between the cooling ring, the liquid passage pipe and the heat pipe in Embodiment 2 of the present application.

[0034] Figure 8 is the sectional view showing the internal structure of the cooling ring in Embodiment 2 of the present application.

[0035] Description of the Reference Numerals: 1. Motor housing; 2. Central shaft; 21. Support part; 211. Plug connector; 22. Transmission part; 23. Positioning part; 231. Connecting bolt; 24. First limiting part; 241. First external spline; 242. First internal spline; 25. Second limiting part; 251. Second external spline; 252. Second internal spline; 3. Motor assembly; 31. Motor stator; 32. Motor rotor; 321. Bearing; 33. Inductive magnetic ring; 34. Magnetic induction encoder; 4. Torque detection sensor; 41. Connecting block; 5. Reduction assembly; 51. Sun gear; 52. Planet gear; 53. Planet carrier; 54. Internal gear ring; 6. Output part; 61. Clutch; 7. Heat dissipation mechanism; 71. Heat transfer ring; 711. Plug-in groove; 72. Cooling ring; 721. Installation groove; 722. Baffle; 73. Temperature sensor; 8. Heat pipe; 81. Sealing ring; 82. Protective mesh cover; 9. Circulating cooling pump; 91. Liquid conveying pipe. Detailed implementation mode

[0036] The following is a further detailed description of the present application in conjunction with the attached Figures 1-8 drawings.

[0037] The embodiment of the present application discloses a mid-mounted motor with a torque detection function.

[0038] Embodiment 1 Referring to Figure 1 and Figure 2 , a mid-mounted motor with a torque detection function includes a motor housing 1, a central shaft 2, a motor assembly 3, a torque detection sensor 4, and a reduction assembly 5. Among them, the central shaft 2 passes through the motor housing 1 and is rotatably connected thereto. The motor assembly 3 is located inside the motor housing 1 and coaxially sleeved on the central shaft 2. The output end of the motor assembly 3 is drivingly connected to the power input end of the reduction assembly 5. The output end of the reduction assembly 5 is connected with an output part 6. The output part 6 is connected to the central shaft 2 through a clutch 61 and extends out of one end of the motor housing 1 and is connected to a sprocket (not shown in the figure) of an electric assist vehicle. The torque detection sensor 4 is located between the motor assembly 3 and the central shaft 2 and is electrically connected to a controller (not shown in the figure) of the electric assist vehicle.

[0039] Referring to Figure 1 and Figure 2, when the rider pedals the footrest while going uphill, the torque detection sensor 4 will sense the magnitude of the pedaling force. Since going uphill requires a greater force to drive the electric assisted bicycle, the pedaling force will increase accordingly. The torque detection sensor 4 captures this signal, converts it into an electrical signal and transmits it to the controller of the electric assisted bicycle. The controller analyzes this signal and determines that the rider is in a working condition such as going uphill that requires assistance. The mid-mounted motor, according to the instructions of the controller, drives the motor assembly 3 to work, so that it outputs corresponding power and drives the reduction assembly 5 to achieve power transmission. Finally, the power is output to the sprocket of the electric assisted bicycle through the clutch 61. The assistance provided by the mid-mounted motor is superimposed on the pedaling force transmitted by the rider through the central shaft 2, thereby reducing the effort of the rider when going uphill and achieving the effect of saving effort.

[0040] Referring to Figure 2 and Figure 3 , the torque detection sensor 4 is located between the motor assembly 3 and the central shaft 2 and is electrically connected to the controller of the electric assisted bicycle. The central shaft 2 includes a support portion 21, a transmission portion 22 and a positioning portion 23. The torque detection sensor 4 is slidably sleeved on the support portion 21, and a first limiting member 24 is arranged between the torque detection sensor 4 and the support portion 21. The first limiting member 24 includes a first external spline 241 and a first internal spline 242. The first external spline 241 is integrally formed on the outer circle of the end of the support portion 21, and the first internal spline 242 is coaxially and fixedly arranged on the end wall of the torque detection sensor 4 facing the first external spline 241. The torque detection sensor 4 is slidably sleeved on the support portion 21 through the insertion fit between the first internal spline 242 and the first external spline 241.

[0041] Referring to Figure 2 and Figure 3 , the transmission portion 22 is coaxially and slidably sleeved on the end of the torque detection sensor 4, and a second limiting member 25 is arranged between the transmission portion 22 and the torque detection sensor 4. The second limiting member 25 includes a second external spline 251 and a second internal spline 252. The second external spline 251 is coaxially and fixedly arranged on the end wall of the torque detection sensor 4 facing away from the first internal spline 242, and the second internal spline 252 is fixedly arranged on the end wall of the transmission portion 22 facing the second external spline 251. The transmission portion 22 is slidably sleeved on the torque detection sensor 4 through the insertion fit between the second internal spline 252 and the second external spline 251, and presses the torque detection sensor 4 against the end wall of the support portion 21 away from the positioning portion 23. The positioning portion 23 coaxially slides through the transmission portion 22 and presses the torque detection sensor 4 against the end wall of the support portion 21 by pushing the transmission portion 22.

[0042] Referring to Figure 2 and Figure 3, in order to push against the transmission part 22 through the end of the positioning part 23, the positioning part 23 slidably penetrates through the transmission part 22, so that the transmission part 22 presses the torque detection sensor 4 against the end of the support part 21, realizing axial limit fixation among the four. An insertion joint 211 with external splines is coaxially and fixedly arranged at one end of the support part 21 facing the positioning part 23. The positioning part 23 is sleeved on the insertion joint 211, and internal splines are arranged on its inner wall to cooperate with the external splines of the insertion joint 211. The positioning part 23 and the insertion joint 211 are axially inserted and matched, and circumferential limit is realized due to the insertion and matching of the internal splines and the external splines. A connecting bolt 231 penetrates through the positioning part 23, and the connecting bolt 231 slidably penetrates through the positioning part 23 and is rotationally connected to the insertion joint 211 through threads.

[0043] Referring to Figure 2 , the motor assembly 3 includes a motor stator 31, a motor rotor 32, an induction magnetic ring 33, and a magnetic induction encoder 34. The motor stator 31 is laminated by silicon steel sheets and has good magnetic conductivity, and is installed and connected to the inner wall of the motor housing 1. The motor rotor 32 is located inside the motor stator 31 and is rotationally connected and assembled to the inner wall of the motor housing 1 through a bearing 321. The induction magnetic ring 33 is coaxially fixed to the end wall of the motor rotor 32, and the induction magnetic ring 33 is made of a high magnetic conductivity material. The magnetic induction encoder 34 is bolted to the inner wall of the motor housing 1 and is coaxially and oppositely arranged with the induction magnetic ring 33. The magnetic induction encoder 34 uses a high-sensitivity sensor and can accurately sense the magnetic field change of the induction magnetic ring 33, so as to determine the specific position and rotation speed of the motor rotor 32. This design not only improves the accuracy of motor operation state monitoring, but also provides reliable data support for the control system of the electric assist vehicle, optimizing the assist effect and energy utilization efficiency of the whole vehicle.

[0044] Referring to Figure 2 , the reduction assembly 5 includes a sun gear 51, a planetary gear 52, a planet carrier 53, and an internal gear ring 54. In this embodiment, two sets of reduction assemblies 5 are provided, and the two sets of reduction assemblies 5 are axially distributed along the central axis 2. Each set of sun gears 51 is rotationally sleeved on the transmission part 22, each set of planet carriers 53 is rotationally sleeved on the transmission part 22 through a bearing 321, the planetary gears 52 in each set are rotatably arranged on the planet carrier 53, the internal gear ring 54 is fixedly arranged on the inner wall of the motor housing 1, and the planetary gears 52 are commonly meshed between the internal gear ring 54 and the sun gear 51. The sun gear 51 close to the motor assembly 3 is coaxially and fixedly connected to the end wall of the motor rotor 32, and the sun gear 51 in the other set is coaxially and fixedly connected to the adjacent planet carrier 53. The planet carrier 53 close to the output part 6 is connected to the output frame through a clutch 61, thus effectively improving the power transmission efficiency and torque output ability of the mid-mounted motor.

[0045] The implementation principle of a mid-mounted motor with a torque detection function in an embodiment of this application is as follows: When a rider pedals uphill, the torque detection sensor 4 rotates synchronously with the central shaft 2 through the spline plug-in fit, thereby sensing the magnitude of the pedaling force. Since more force is required to drive the electric assist vehicle uphill, the pedaling force will increase accordingly. The torque detection sensor 4 captures this signal, converts it into an electrical signal, and transmits it to the controller of the electric assist vehicle. The controller analyzes this signal and determines that the rider is in a working condition such as uphill that requires assistance. The mid-mounted motor drives the motor assembly 3 to work according to the instructions of the controller. At this time, the motor rotor 32 rotates to output corresponding power, and the power is transmitted through the meshing transmission of multiple sets of sun gears 51 and planet gears 52. Finally, the power is output to the sprocket of the electric assist vehicle through the clutch 61. The assistance provided by the mid-mounted motor is superimposed on the pedaling force transmitted by the rider through the central shaft 2, thereby reducing the force exerted by the rider uphill and achieving a labor-saving effect.

[0046] Embodiment 2 Refer to Figure 4 and Figure 5 In this embodiment, the difference from Embodiment 1 is that a heat dissipation mechanism 7 for dissipating heat from the torque detection sensor 4 is provided inside the motor housing 1.

[0047] Refer to Figure 4 、 Figure 5 and Figure 6 In this embodiment, the heat dissipation mechanism 7 includes a heat transfer ring 71, a cooling ring 72, and a temperature sensor 73. Both the heat transfer ring 71 and the cooling ring 72 are made of high thermal conductivity materials. The cooling ring 72 is fixed on the inner wall of the motor housing 1. The inner cavity of the cooling ring 72 is filled with a cooling liquid. The heat transfer ring 71 is rotatably connected to the inner ring of the cooling ring 72 facing the torque detection sensor 4. The end wall of the torque detection sensor 4 facing the heat transfer ring 71 is a thermosensitive part, and a plurality of integrally formed connection blocks 41 are arranged along its circumferential direction. In this embodiment, two are taken as examples, and the two connection blocks 41 are distributed radially along the heat transfer ring 71. A plug-in slot 711 is recessed on the heat transfer ring 71 corresponding to each connection block 41, and the connection block 41 is in plug-in fit with the corresponding plug-in slot 711. The temperature sensor 73 is adhesively mounted on the side wall of the cooling ring 72 facing the torque detection sensor 4.

[0048] Refer to Figure 4 and Figure 7, a plurality of mounting grooves 721 are provided on the cooling ring 72. In this embodiment, three are taken as an example. A heat pipe 8 is inserted into each mounting groove 721. The heating end of the heat pipe 8 is inserted into the mounting groove 721 and is glued to the cooling ring 72 through heat-conducting glue. The condensing end of the heat pipe 8 penetrates out of the motor housing 1, and a sealing ring 81 is fixedly connected to the connection part of the heat pipe 8 and the motor housing 1. A protective mesh cover 82 is sleeved on the condensing end of each heat pipe 8 extending out of the motor housing 1. The protective mesh cover 82 is glued to the motor housing 1, effectively protecting the condensing end of the heat pipe 8 and reducing the risk of damage due to accidental collision or friction in the external environment.

[0049] Referring to Figure 4 , Figure 7 and Figure 8 , a circulating cooling pump 9 is installed on the outer wall of the motor housing 1. The circulating cooling pump 9 is electrically connected to the temperature sensor 73. A partition plate 722 is fixedly arranged in the cooling ring 72. The partition plate 722 divides the cooling liquid into an orderly flow path. On both sides of the partition plate 722 on the cooling ring 72, a liquid pipe 91 is respectively communicated with the inner cavity. The pipe ends of the two liquid pipes 91 penetrate out of the motor housing 1 and are respectively connected to the inlet and outlet ends of the circulating cooling pump 9.

[0050] The implementation principle of Embodiment 2 is: during the operation of the mid-mounted motor, the temperature sensor 73 monitors the temperature change inside the motor in real time. Within a reasonable temperature range, the heating end of the heat pipe 8 is tightly connected to the cooling ring 72, and can quickly transfer the heat in the cooling ring 72 to the condensing end outside the motor housing 1 and dissipate it to the external environment, improving the stability performance of the torque detection sensor 4.

[0051] When encountering the special situation of too high temperature inside the motor housing 1, under the monitoring of the temperature sensor 73 and with the driving effect of the circulating cooling pump 9, the flow rate of the cooling liquid can be effectively controlled, so as to quickly take away the heat absorbed by the cooling ring 72. Further improve the stability performance of the torque detection sensor 4 under different working conditions.

[0052] The above are all the preferred embodiments of this application. The protection scope of this application is not limited by this. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A mid-mounted motor with a torque detection function, characterized in that , including a motor housing (1), a central shaft (2), a motor assembly (3), a torque detection sensor (4), and a reduction assembly (5). The central shaft (2) passes through the motor housing (1) and is rotatably connected to the motor housing (1). The motor assembly (3) is located inside the motor housing (1) and is coaxially sleeved on the central shaft (2). The torque detection sensor (4) is located between the motor assembly (3) and the central shaft (2) and is electrically connected to the controller of the electric assist vehicle. The central shaft (2) includes a support portion (21), a transmission portion (22), and a positioning portion (23) that are coaxially arranged. The torque detection sensor (4) is slidably sleeved on the support portion (21), and a first limiting member (24) for circumferential limitation is provided between the torque detection sensor (4) and the support portion (21). The transmission portion (22) is coaxially slidably sleeved on the end of the torque detection sensor (4), and a second limiting member (25) for circumferential limitation is provided between the transmission portion (22) and the torque detection sensor (4). The positioning portion (23) coaxially slidably passes through the transmission portion (22), and the torque detection sensor (4) is pressed against the end wall of the support portion (21) by pushing the transmission portion (22).

2. The mid-mounted motor with a torque detection function according to claim 1, characterized in that , The first limiting member (24) includes a first external spline (241) provided around the end of the support portion (21) and a first internal spline (242) provided on the side end wall of the torque detection sensor (4). The torque detection sensor (4) is slidably sleeved on the support portion (21) through the insertion fit between the first internal spline (242) and the first external spline (241). The second limiting member (25) includes a second external spline (251) coaxially provided on the other end wall of the torque detection sensor (4) and a second internal spline (252) provided on the side end wall of the transmission portion (22). The transmission portion (22) is slidably sleeved on the torque detection sensor (4) through the insertion fit between the second internal spline (252) and the second external spline (251), and the torque detection sensor (4) is pressed against the end wall of the support portion (21) away from the positioning portion (23).

3. The mid-mounted motor with a torque detection function according to claim 2, characterized in that , One end of the support portion (21) facing the positioning portion (23) is provided with a plug joint (211) with external splines. The positioning portion (23) is sleeved on the plug joint (211), and internal splines are provided on its inner wall to cooperate with the external splines of the plug joint (211). The positioning portion (23) and the plug joint (211) are axially inserted and matched. A connecting bolt (231) is inserted into the positioning portion (23). The connecting bolt (231) slidably passes through the positioning portion (23) and is rotationally connected to the plug joint (211) by threads.

4. The mid-mounted motor with a torque detection function according to claim 1, characterized in that , The motor assembly (3) includes a motor stator (31), a motor rotor (32), an induction magnetic ring (33) and a magnetic induction encoder (34). The motor rotor (32) is installed on the inner wall of the motor housing (1). The motor rotor (32) is located inside the inner ring of the motor stator (31) and is rotatably connected to the inner wall of the motor housing (1) through a bearing (321). The induction magnetic ring (33) is coaxially arranged on the end wall of the motor rotor (32). The magnetic induction encoder (34) is arranged on the inner wall of the motor housing (1) and is coaxially opposite to the induction magnetic ring (33).

5. A mid-mounted motor with a torque detection function according to claim 1, characterized in that , The output end of the motor assembly (3) is drivingly connected to the power input end of the reduction assembly (5). The output end of the reduction assembly (5) is connected with an output member (6). The output member (6) is connected to the middle shaft (2) through a clutch (61). And one end of the output member (6) extending out of the motor housing (1) is connected to the sprocket of the electric assist vehicle. The reduction assembly (5) includes a sun gear (51), planet gears (52), a planet carrier (53) and an internal gear ring (54). Both the sun gear (51) and the planet carrier (53) are rotatably sleeved on the transmission part (22). The sun gear (51) is coaxially connected to the end wall of the motor rotor (32). The planet gears (52) are meshed with the sun gear (51) and are rotatably arranged on the planet carrier (53). The internal gear ring (54) is arranged on the inner wall of the motor housing (1) and is meshed and sleeved on the planet gears (52). The output member (6) is connected to the planet carrier (53) through a clutch (61).

6. The mid-mounted motor with a torque detection function according to claim 5, characterized in that , Multiple groups of the reduction assembly (5) are axially distributed along the middle shaft (2) inside the motor housing (1). Between adjacent two groups of the reduction assembly (5), adjacent sun gears (51) are connected to the planet carrier (53) of the adjacent group.

7. The mid-mounted motor with a torque detection function according to claim 1, characterized in that , A heat dissipation mechanism (7) for dissipating heat from the torque detection sensor (4) is arranged inside the motor housing (1). The heat dissipation mechanism (7) includes a heat transfer ring (71), a cooling ring (72) and a temperature sensor (73). The cooling ring (72) is fixed on the inner wall of the motor housing (1). The heat transfer ring (71) is rotatably connected to the inner ring of the cooling ring (72) facing the torque detection sensor (4). The end wall of the torque detection sensor (4) facing the heat transfer ring (71) is a thermosensitive part, and a connecting block (41) is arranged on the outer side wall of its outer ring. A plugging slot (711) is concavely arranged on the heat transfer ring (71). The connecting block (41) is in plugging fit with the plugging slot (711).

8. A mid-mounted motor with a torque detection function according to claim 7, characterized in that , The inner cavity of the cooling ring (72) is filled with cooling liquid. A circulating cooling pump (9) electrically connected to the temperature sensor (73) is arranged on the outer wall of the motor housing (1). A flow dividing plate (722) is arranged inside the cooling ring (72). A liquid passing pipe (91) is respectively communicated with the inner cavity on both sides of the flow dividing plate (722) on the cooling ring (72). The pipe ends of the two liquid passing pipes (91) penetrate out of the motor housing (1) and are respectively connected to the inlet and outlet ends of the circulating cooling pump (9).

9. The mid-mounted motor with torque detection function according to claim 8, characterized in that ,A plurality of mounting grooves (721) are provided on the cooling ring (72). A heat pipe (8) is inserted into each mounting groove (721). The heating end of the heat pipe (8) is inserted into the mounting groove (721) and is adhesively bonded to the cooling ring (72) through a thermal conductive adhesive. The condensation end of the heat pipe (8) penetrates out of the motor housing (1), and a sealing ring (81) is sleeved at the connection between the heat pipe (8) and the motor housing (1).

10. The mid-mounted motor with a torque detection function according to claim 9, characterized in that ,A protective net cover (82) is sleeved on the condensation end of each heat pipe (8) extending out of the motor housing (1), and the protective net cover (82) is connected to the motor housing (1).

Images