A mid-motor with torque sensor and electric bicycle thereof

Abstract

The utility model relates to a middle -placed motor with torque sensor and electric bicycle thereof, including moment generator, plane bearing and torque inductor, moment generator, plane bearing set up in the gear disc frame of middle -placed motor, and set up on the outer wall of hollow shaft of middle -placed motor, moment generator is connected through spline with hollow shaft, torque inductor sets up in the motor casing of middle -placed motor, when hollow shaft rotates relative gear disc frame, moment generator rotates along with, simultaneously promotes plane bearing axial movement, torque inductor senses the displacement signal of plane bearing axial movement, and sends the electric signal to the controller of middle -placed motor with displacement signal conversion, thereby, plane bearing axle has absorbed torque generator rotation to torque inductor scratch damage, signal accurate and stable, has increased the life.

Description

Technical Field

[0001] This utility model relates to the field of mid-drive motor technology, and in particular to a mid-drive motor with a torque sensor and an electric bicycle thereof. Background Technology

[0002] Currently, with the popularization of environmental protection knowledge and the increasing environmental awareness of people, green travel has become a trend. Bicycles have become an important means of transportation for people's green travel, and as the bicycle market gradually expands, people's requirements for bicycles are also getting higher and higher.

[0003] With the development of technology, bicycles have been transformed from purely human-powered to purely electric-powered. With changes in consumption concepts and environmental awareness, electric vehicles are now beginning to transform into hybrid electric vehicles.

[0004] In the field of electric power assist sensors for bicycles, Chinese patent CN102494826A discloses a "gear-type dual-position sensor," which includes a central shaft, a bushing housing the central shaft, a gear disk fixed on the central shaft, multiple spring mounting holes on the gear disk, a positioning seat on the bushing, a Hall sensor seat placed on the positioning seat, a gear disk thrust base fixedly connected to the edge of the central hole of the gear disk, and the gear disk fixed to the central shaft by the gear disk thrust base, and a claw crank and a fixing cover are provided. The claw crank and the fixing cover are connected at the spring mounting holes, and their common connection end is limited to movement within the spring mounting holes. The Hall sensor seat is provided with Hall elements distributed axially and radially, and a movable torque axial converter assembly with an annular magnet is placed in the hollow cavity formed by the Hall sensor seat, the central hole of the gear disk and the claw crank in sequence; the vehicle's power-assisted rotation is controlled by the axial and radial electrical signals collected by the Hall elements.

[0005] However, this patent does not have a hollow shaft and is only suitable for use with rear hub motors. When used with a mid-drive motor, the motor directly drives the rotation of the central shaft, causing the pedal force to be unable to act on the central shaft, resulting in the signal being unable to be measured. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a mid-mounted motor with torque sensor and its electric bicycle. Its advantages are that it is responsive and fast, accurate in positioning, has good linearity in signal output and few "gaps", which can improve the accuracy and reliability of torque signal, making riding easier and significantly improving riding comfort, especially when climbing hills.

[0007] The above-mentioned utility model objective is achieved through the following technical solution: On one hand, this utility model provides a mid-drive motor with a torque sensor, including a motor housing, a hollow shaft rotatably disposed within the motor housing, and a gear frame rotatable with the hollow shaft; it also includes a torque generator, a planar bearing, and a torque sensor; the torque generator and the planar bearing are both disposed within the gear frame of the mid-drive motor and sleeved on the outer peripheral wall of the hollow shaft of the mid-drive motor; the torque generator is connected to the hollow shaft via a spline; the torque sensor is disposed within the motor housing of the mid-drive motor; when the hollow shaft rotates relative to the gear frame, the torque generator generates torque with the rotation, simultaneously pushing the planar bearing to move axially; the torque sensor senses the displacement signal of the axial movement of the planar bearing and converts the displacement signal into an electrical signal, which is then sent to the controller of the mid-drive motor.

[0008] Preferably, the mid-mounted motor with torque sensor provided by this utility model includes a torque generator comprising a body, multiple elastic elements, multiple steel balls, and multiple limiting posts; the body is sleeved on the outer peripheral wall near one end of the hollow shaft, and the body is splinedly connected to the hollow shaft; multiple first limiting blocks are provided on the body, and the multiple first limiting blocks are spaced apart circumferentially around the body; multiple second limiting blocks are provided inside the gear frame, and the multiple second limiting blocks are spaced apart circumferentially around the gear frame; the elastic elements are disposed between the first limiting blocks and the second limiting blocks. Between the position blocks; each of the second limiting blocks has a curved groove, and the main body has a linkage through hole. The steel ball is placed between the curved groove and the linkage through hole; the second limiting block has a limiting post, and the main body has a sliding hole. The limiting post passes through the sliding hole and can slide relative to it; when the hollow shaft drives the main body to rotate relative to the gear plate frame, the limiting post and the sliding hole limit the rotation angle. The elastic element is squeezed by the first limiting block and the second limiting block, and the steel ball pushes the planar bearing to move axially under the action of the curved groove.

[0009] Preferably, the mid-mounted motor with torque sensor provided by this utility model includes a curved groove comprising a semi-circular groove and an inclined surface. The inclined surface is disposed on the inner wall of the semi-circular groove on the side away from the limiting post located on the same second limiting block. In the initial state, the steel ball is located in the semi-circular groove. When a torque is generated, the central shaft rotates clockwise, driving the hollow shaft to rotate. The rotation of the hollow shaft drives the main body to rotate synchronously. The rotation of the main body drives the steel ball to move circumferentially. Under the action of the inclined surface, the steel ball moves axially along the inclined surface. The steel ball passes through the linkage hole and is pressed against the planar bearing, so that the planar bearing moves axially along the hollow shaft.

[0010] Preferably, the mid-mounted motor with torque sensor provided by this utility model includes a first tube and an annular disk, one end of the first tube is connected to the annular disk; a plurality of first limiting blocks are disposed on the side of the annular disk facing the first tube, and the sliding hole and the linkage through hole are both opened on the annular disk; the first tube is splined to the hollow shaft.

[0011] Preferably, the mid-mounted motor with torque sensor provided by this utility model includes a gear frame comprising a column and multiple fixed gear plates; a cavity is formed at the first end of the column, and the main body is accommodated in the cavity; a through hole is formed at the second end of the column, the through hole communicating with the cavity, and the first tube is rotatably inserted into the through hole; a receiving groove for accommodating an elastic element is provided at the bottom of the cavity, and multiple second limiting blocks are all disposed in the receiving groove; multiple fixed gear plates are all disposed at the second end of the column, the multiple fixed gear plates are spaced apart around the circumference of the column, and the multiple fixed gear plates extend outward along the radial direction of the column.

[0012] Preferably, the mid-mounted motor with torque sensor provided by this utility model further includes an end cover, a limiting step is formed at the end of the hollow shaft, the end cover is detachably connected to the hollow shaft, and the limiting step and the end cover clamp the body and the gear frame.

[0013] Preferably, in the mid-mounted motor with torque sensor provided by this utility model, a wear-resistant ring is provided in the through hole, and the first tube body is rotatably inserted into the wear-resistant ring.

[0014] Preferably, the mid-mounted motor with torque sensor provided by this utility model is characterized in that: a plurality of reset elastic bodies are provided on the motor housing, the plurality of reset elastic bodies are spaced apart circumferentially and abut against the planar bearing; when the torque weakens or disappears, the reset elastic bodies apply a restoring force to the planar bearing to move the planar bearing to the initial position.

[0015] Preferably, the present invention provides a mid-drive motor with a torque sensor, wherein the torque sensor includes a magnet, a spring plate, a Hall sensor, and an arc-shaped circuit board. The spring plate is inclinedly disposed on the arc-shaped circuit board, one end of the spring plate is connected to one end of the arc-shaped circuit board, and the free end of the spring plate is connected to the magnet. The Hall sensor is disposed on the arc-shaped circuit board, and the arc-shaped circuit board is fixed inside the motor housing. When the planar bearing moves axially along the hollow shaft, the planar bearing compresses the magnet to push the magnet toward the arc-shaped circuit board. The Hall sensor detects the displacement of the magnet and converts the displacement into an electrical signal.

[0016] On the other hand, this utility model provides an electric bicycle having a mid-mounted motor with a torque sensor as described above.

[0017] In summary, the beneficial technical effects of this utility model are as follows: The mid-drive motor with torque sensor and the electric bicycle provided in this application have a mid-drive motor with torque sensor. The mid-drive motor includes a torque generator, a planar bearing, and a torque sensor. The torque generator and the planar bearing are disposed inside the gear frame of the mid-drive motor and sleeved on the outer peripheral wall of the hollow shaft of the mid-drive motor. The torque generator and the hollow shaft are connected by a spline. The torque sensor is disposed inside the motor housing of the mid-drive motor. When the hollow shaft rotates relative to the gear frame, the torque generator rotates along with it, and at the same time pushes the planar bearing to move axially. The torque sensor senses the displacement signal of the axial movement of the planar bearing and converts the displacement signal into an electrical signal and sends it to the controller of the mid-drive motor. Thus, the planar bearing shaft absorbs the friction damage to the torque sensor caused by the rotation of the torque generator, the signal is accurate and stable, and the service life is increased. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the torque sensor in the mid-mounted motor with torque sensor provided in this embodiment of the utility model.

[0019] Figure 2 This is a cross-sectional view of a mid-mounted motor with a torque sensor, provided in an embodiment of the present invention, in which the torque sensor is mounted on the motor housing.

[0020] Figure 3 This is a schematic diagram of the torque generator in a mid-mounted motor with a torque sensor provided in this embodiment of the utility model.

[0021] Figure 4 This is a schematic diagram of the torque sensor structure in a mid-mounted motor with a torque sensor provided in an embodiment of this utility model.

[0022] Figure 5 This is a schematic diagram of the structure of the gear frame of the mid-mounted motor with torque sensor provided in this embodiment of the utility model.

[0023] Figure 6 This is a schematic diagram of the structure of the motor housing in the mid-mounted motor with torque sensor provided in this embodiment of the utility model.

[0024] In the diagram, 1. Torque sensor; 10. Torque generator; 11. Body; 111. First tube; 112. Second tube; 113. Annular disk; 1131. First limiting block; 1132. Sliding hole; 1133. Linkage through hole; 12. Elastic element; 13. Steel ball; 14. Limiting post; 20. Planar bearing; 30. Torque sensor; 31. Magnet; 32. Spring plate; 33. Hall sensor; 34. Arc-shaped circuit board; 40. Wear-resistant ring; 50. Reset elastic body; 2. Gear frame; 21. Column; 211. Cavity; 2111. Second limiting block; 2112. Curved groove; 2113. Semi-circular groove; 2114. Inclined surface; 212. Through hole; 22. Fixed toothed plate; 3. End cap; 301. Fixed sleeve; 302. Limiting flange; 4. Motor housing; 41. First cylinder; 42. Second cylinder; 421. Mounting groove; 4211. Protrusion; 4212. Space; 5. Hollow shaft. Detailed Implementation

[0025] The present invention will be further described in detail below with reference to the accompanying drawings.

[0026] Reference Figure 1 and Figure 2 This utility model discloses a mid-mounted motor with a torque sensor, comprising a motor housing 4, a hollow shaft 5 rotatably disposed within the motor housing 4, and a gear rack 2 rotatable with the hollow shaft 5; a central shaft for connecting to a foot pedal is inserted inside the hollow shaft 5, and a gap is left between the outer peripheral wall of the central shaft and the inner peripheral wall of the hollow shaft 5; an overrunning clutch and two bearings are both sleeved on the central shaft and located inside the hollow shaft 5, with the two bearings located at opposite ends of the overrunning clutch; the central shaft is connected to the hollow shaft 5 via the overrunning clutch; when the central shaft rotates forward, the overrunning clutch is subjected to force to drive the hollow shaft 5 to rotate; when the central shaft rotates in reverse, the overrunning clutch is not subjected to force, thereby disengaging the power transmission between the central shaft and the hollow shaft 5.

[0027] Specifically, the center line of the central axis is set parallel to the center line of the hollow shaft 5. In some feasible ways, the center line of the central axis is set collinear with the center line of the hollow shaft 5. Both ends of the central axis extend to the outside of the hollow shaft and are equipped with foot pedals.

[0028] In this embodiment, the overrunning clutch adopts a ratchet mechanism so that the overrunning clutch can achieve the effect of being force-bearing in forward rotation and not being force-bearing in reverse rotation.

[0029] The mid-drive motor with torque sensor provided in this embodiment also includes a torque generator 10, a planar bearing 20, and a torque sensor 30. The torque generator 10 and the planar bearing 20 are both disposed inside the gear frame 2 of the mid-drive motor and sleeved on the outer peripheral wall of the hollow shaft 5 of the mid-drive motor. The torque generator 10 and the hollow shaft 5 are connected by a spline. The torque sensor 30 is disposed inside the motor housing 4 of the mid-drive motor. When the hollow shaft 5 rotates relative to the gear frame 2, the torque generator 10 generates torque as it rotates, which simultaneously pushes the planar bearing shaft 20 to move. The torque sensor 30 senses the displacement signal of the planar bearing shaft 20 moving in the direction of rotation and converts the displacement signal into an electrical signal and sends it to the controller of the mid-drive motor. Thus, the planar bearing 20 shaft absorbs the friction damage to the torque sensor 30 caused by the rotation of the torque generator 10, resulting in a precise and stable signal and increased service life.

[0030] When the central shaft rotates forward, the central shaft drives the hollow shaft 5 to rotate through the overrunning clutch, and the hollow shaft 5 drives the torque generator 10 to rotate synchronously.

[0031] Continue to refer to Figure 6 In this embodiment, the motor housing 4 includes a first cylinder 41 and a second cylinder 42. The center line of the first cylinder 41 is perpendicular to the center line of the second cylinder 42. The first cylinder 41 and the second cylinder 42 are connected and together form a T-shape. The first end of the first cylinder 41 is sealed. One end of the hollow shaft 5 is inserted into the second cylinder 42, and the other end of the hollow shaft 5 extends to the outside of the second cylinder 42 and the end cap is inserted into the torque generator 10.

[0032] The second cylinder 42 has an inwardly recessed mounting groove 421 at one end, and multiple protrusions 4211 are provided in the mounting groove 421. The multiple protrusions 4211 are arranged at intervals along the circumference of the second cylinder 42, and a space 4212 is left between each two adjacent protrusions 4211. The torque sensor 30 is fixed in the space 4212 between two adjacent protrusions 4211. The space 4212 is located close to the first cylinder 41.

[0033] like Figure 6 As shown, there are 3 bumps 4211. Of course, there can also be 4 or 5 bumps 4211.

[0034] Continue to refer to Figures 1 to 3In this embodiment, the torque generator 10 includes a body 11, a plurality of elastic elements 12, a plurality of steel balls 13 and a plurality of limiting posts 14. The body 11 is sleeved on the outer peripheral wall near one end of the hollow shaft 5. The body 11 is splined connected to the hollow shaft 5. A plurality of first limiting blocks 1131 are provided on the body 11. The plurality of first limiting blocks 1131 are spaced apart around the circumference of the body 11. A plurality of second limiting blocks 2111 are provided inside the gear frame 2. The plurality of second limiting blocks 2111 are spaced apart around the circumference of the gear frame 2. The elastic element 12 is disposed between the first limiting block 1131 and the second limiting block 2111; each second limiting block 2111 is provided with a curved groove 2112, and the curved groove 2112 is provided in a one-to-one correspondence with the steel ball 13. The main body 11 is provided with a linkage through hole 1133, and the steel ball 13 is placed between the curved groove 2112 and the linkage through hole 1133; the second limiting block 2111 is provided with a limiting post 14, and the main body 11 is provided with a sliding hole 1132, through which the limiting post 14 passes and can slide relative to each other.

[0035] During use, when the hollow shaft 5 drives the body 11 to rotate relative to the gear frame 2, the limiting post 14 and the sliding hole 1132 limit the rotation angle, the elastic element 12 is squeezed by the first limiting block 1131 and the second limiting block 2111, and the steel ball 13 pushes the plane bearing shaft 20 to move under the action of the curved groove 2112.

[0036] Specifically, one end of the elastic element 12 contacts the side wall of the first limiting block 1131, and the other end of the elastic element 12 contacts the side wall of the second limiting block 2111. A sliding hole 1132 and a linkage through hole 1133 are provided between each two adjacent first limiting blocks 1131. The sliding hole 1132 and the limiting post 14 are arranged in a one-to-one correspondence. The steel ball 13 and the linkage through hole 1133 are arranged in a one-to-one correspondence. One end of the limiting post 14 passes through the sliding hole 1132 and is inserted into the second limiting block 2111. The limiting post 14 can slide along the sliding hole 1132.

[0037] During use, the hollow shaft 5 rotates, causing the main body 11 to rotate synchronously. The rotation of the main body 11 causes the steel ball 13 to move circumferentially. Under the action of the curved groove 2112, the steel ball 13 changes from circumferential movement to axial movement. The steel ball 13 passes through the linkage through hole 1133 and squeezes the plane bearing 20, pushing the plane bearing 20 to move along the axial direction of the hollow shaft 5. At the same time, when the main body 11 rotates, each elastic element 12 is compressed. The force generated by squeezing the elastic element 12 acts on the second limit block 2111, and the gear plate frame 2 rotates under the force of the elastic element 12.

[0038] It should be noted that the number of the first limiting block 1131 is basically the same as the number of the second limiting block 2111, the number of the first limiting block 1131 is basically the same as the number of the elastic element 12, the number of steel ball 13 is basically the same as the number of the linkage through hole 1133, and the number of limiting post 14 is basically the same as the number of sliding hole 1132.

[0039] For example, the limiting post can be a limiting pin, or of course, the limiting post can also be a limiting screw.

[0040] In this embodiment, as Figure 3 As shown, the number of the first limiting block 1131, sliding hole 1132, limiting post 14, steel ball 13 and linkage through hole 1133 are all 3; of course, the number of the first limiting block 1131, sliding hole 1132, limiting post 14, steel ball 13 and linkage through hole 1133 can also be 4 or 5.

[0041] For example, the elastic element 12 can be a helical spring; of course, the elastic element can also be a resilient cylinder.

[0042] Furthermore, in this embodiment, the body 11 includes a first tube 111 and an annular disk 113. One end of the first tube 111 is connected to the annular disk 113. A plurality of first limiting blocks 1131 are disposed on the side of the annular disk 113 facing the first tube 111. Sliding holes 1132 and linkage through holes 1133 are both opened on the annular disk 113. The first tube 111 is splinedly connected to the hollow shaft 5.

[0043] Specifically, the main body 11 also includes a second tube 112. One end of the first tube 111 with an annular disk 113 is connected to one end of the second tube 112. A plurality of first limiting blocks 1131 are arranged at intervals along the circumference of the annular disk 113. Sliding holes 1132 and linkage through holes 1133 are both opened on the annular disk 113, and the sliding holes 1132 and linkage through holes 1133 both penetrate the annular disk 113.

[0044] An annular boss is provided on the outer peripheral wall of the end of the first tube 111 facing the annular disk 113. The annular boss extends radially outward along the first tube 111 to the first limiting block 1131.

[0045] Continue to refer to Figure 5In this embodiment, the gear plate frame 2 includes a column 21 and a plurality of fixed gear plates 22. The first end of the column 21 has a cavity 211, and the body 11 is accommodated in the cavity 211. The second end of the column 21 has a through hole 212, which communicates with the cavity 211. The first tube 111 is rotatably inserted into the through hole 212. The bottom of the cavity 211 is provided with a receiving groove for accommodating the elastic element. A plurality of second limiting blocks 2111 are all disposed in the receiving groove. The plurality of second limiting blocks 2111 are spaced apart along the circumference of the cavity 211. A plurality of fixed gear plates 22 are all disposed at the second end of the column 21. The plurality of fixed gear plates 22 are spaced apart around the circumference of the column 21. The plurality of fixed gear plates 22 extend outward along the radial direction of the column 21.

[0046] During installation, the first tube 111 is inserted into the through hole 212, the second tube 112 and the annular disc 113 are both located in the cavity 211, the elastic element 12 and the first limiting block 1131 are both inserted into the receiving groove, and the elastic element 12 is located between the first limiting block 1131 and the second limiting block 2111.

[0047] like Figure 5 As shown, there are 3 second limit blocks 2111. Of course, there can also be 4 or 5 second limit blocks 2111.

[0048] During use, the hollow shaft 5 rotates, causing the main body 11 to rotate. The elastic element 12 is compressed between the first limiting block 1131 and the second limiting block 2111. The compression distance of the elastic element 12 (i.e., the rotatable distance) is the circumferential sliding distance of the limiting post 14 relative to the sliding hole 1132. If the elastic element 12 is fully compressed, the limiting post 14 slides from one end of the sliding hole 1132 to the other end of the sliding hole 1132.

[0049] Furthermore, in this embodiment, a wear-resistant ring 40 is provided inside the through hole 212, and the first tube 111 is rotatably inserted into the wear-resistant ring 40; by providing the wear-resistant ring 40, the service life of the gear plate frame is improved.

[0050] Furthermore, the mid-mounted motor with torque sensor provided in this embodiment also includes an end cover 3, and a limiting step is formed at the end of the hollow shaft 5. The end cover 3 is detachably connected to the hollow shaft 5, and the limiting step and the end cover 3 clamp the body 11 and the gear plate frame 2.

[0051] To prevent the torque generator 10 from moving axially along the hollow shaft 5, the end cover 3 includes a fixed sleeve 301 and a limiting flange 302. The outer peripheral wall of the fixed sleeve 301 is provided with an external thread. The hollow shaft has an internal thread that matches the external thread at one end with a limiting step. One end of the fixed sleeve 301 is screwed into the protruding end of the hollow shaft 5. The fixed sleeve 301 is threadedly connected to the hollow shaft 5. The other end of the fixed sleeve 301 extends to the outside of the hollow shaft 5 and is provided with a limiting flange 302. The limiting flange 302 extends radially outward along the fixed sleeve 301 and is located in the through hole.

[0052] Furthermore, in this embodiment, the curved groove 2112 includes a semi-circular groove 2113 and an inclined surface 2114. The inclined surface 2114 is disposed on the inner wall of the semi-circular groove 2113 on the side away from the limiting post located on the same second limiting block 2111. By setting the inclined surface 2114, the circumferential movement of the steel ball 13 can be converted into axial movement, thereby improving the accuracy of detection.

[0053] In the initial state, the steel ball 13 is located in the semi-circular groove 2113. When a torque is generated (that is, when the central shaft and the chain have opposite forces), the central shaft rotates clockwise, driving the hollow shaft to rotate. The rotation of the hollow shaft drives the body to rotate synchronously. The rotation of the body drives the steel ball to move circumferentially. Under the action of the inclined surface, the steel ball 13 moves axially along the inclined surface 2114. The steel ball 13 passes through the linkage hole and is pressed against the flat bearing 20, so that the flat bearing 20 moves axially along the hollow shaft 5.

[0054] Specifically, inclined surface 2114 adopts a 45° incline.

[0055] Under normal conditions, the steel ball 13 is located in the semi-circular groove 2113 and partly in the linkage through hole 1133. When the hollow shaft 5 rotates and drives the body 11 to rotate synchronously, the inclined surface 2114 squeezes the steel ball 13 to move along the inclined surface 2114.

[0056] It should be noted that the movement of steel ball 13 is changed from circumferential to axial, and the ratio of movement is 1:1.

[0057] Furthermore, in this embodiment, the torque sensor 1 also includes a plurality of reset elastic bodies 50, which are spaced apart circumferentially and abut against the planar bearing 20; when the torque weakens or disappears, the reset elastic bodies 50 apply a restoring force to the planar bearing 20 so that the planar bearing 20 moves to the initial position.

[0058] Specifically, the reset elastic body 50 is provided in a one-to-one correspondence with the protrusion 4211. Each protrusion 4211 has a mounting hole extending along the center line of the second cylinder 42. The tail of the reset elastic body 50 is inserted into the mounting hole of the protrusion 4211, and the top of the reset elastic body 50 extends outward along the center line of the second cylinder 42 and contacts the side of the plane bearing 20 facing the torque sensor 30.

[0059] For example, the reset elastomer 50 may be a pin. The tips of a plurality of pins contact the side of the planar bearing 20 facing the torque sensor 30, and the tails of the plurality of pins are fixed inside the motor housing 4.

[0060] It should be noted that the structure of the planar bearing 20 is well known to those skilled in the art, and the structure of the planar bearing 20 will not be described in detail here.

[0061] When the steel ball 13 passes through the linkage through hole 1133 and squeezes the hyperboloid ring of the plane bearing 20, the hyperboloid ring is forced to move under force and rotates slightly. The rotation speed is reduced by the hyperboloid ring and the balls on the plane bearing 20 in sequence. When it reaches the fixed ring on the plane bearing 20, the fixed ring only makes horizontal displacement.

[0062] Continue to refer to Figure 4 In this embodiment, the torque sensor 30 includes a magnet 31, a spring plate 32, a Hall sensor 33, and an arc-shaped circuit board 34. The spring plate 32 is inclinedly disposed on the arc-shaped circuit board 34, with one end of the spring plate 32 connected to one end of the arc-shaped circuit board 34 and the free end of the spring plate 32 connected to the magnet 31. The Hall sensor 33 is disposed on the arc-shaped circuit board 34, and the arc-shaped circuit board 34 is fixed inside the motor housing 4. When the planar bearing 20 moves along the axial direction of the hollow shaft 5, the planar bearing 20 squeezes the magnet 31 to push the magnet 31 to move towards the arc-shaped circuit board 34. The Hall sensor 33 detects the displacement of the magnet 31 as a torque signal and converts the displacement into an electrical signal.

[0063] Specifically, the arc-shaped circuit board 34 is fixed in the space 4212 on the side near the first cylinder 41. The spring sheet 32 ​​is elastic.

[0064] During use, when the steel ball 13 passes through the linkage through hole 1133 and squeezes the plane bearing 20, the plane bearing 20 moves along the axial direction of the hollow shaft 5 and squeezes the magnet 31. The displacement of the magnet 31 is detected by the Hall sensor 33. The larger the area of ​​the corresponding position of the magnet 31 and the Hall sensor 33, the greater the resistance generated and the greater the electrical signal. In other words, the magnitude of the torque is determined based on the displacement of the magnet 31.

[0065] It should be noted that the Hall sensor 33 detects voltage values.

[0066] The working principle of the torque sensor 1 of the mid-drive motor provided in this embodiment is as follows: When the bicycle starts, the sprocket does not rotate, the hollow shaft 5 rotates and drives the body 11 to rotate synchronously. The limiting post 14 and the sliding hole 1132 limit the rotation angle. The rotation of the body 11 drives the steel ball 13 to move circumferentially. Under the action of the curved groove 2112, the steel ball 13 changes from circumferential movement to axial movement. The steel ball 13 passes through the linkage through hole 1133 and squeezes the plane bearing 20, pushing the plane bearing 20 to move axially along the hollow shaft 5. The plane bearing 20 squeezes the magnet 31 to push the magnet 31 to move towards the arc circuit board 34. The Hall sensor 33 detects the displacement of the magnet 31 as a torque signal and converts the displacement into an electrical signal. At the same time, the elastic element 12 is squeezed by the first limiting block 1131 and the second limiting block 2111. The force generated by squeezing the elastic element 12 acts on the second limiting block 2111, so that the gear frame 2 rotates, thereby driving the sprocket to rotate.

[0067] Another embodiment provides an electric bicycle having a mid-mounted motor with a torque sensor as described above.

[0068] Specifically, the mid-drive motor is installed inside the electric bicycle body, and both ends of the central shaft of the mid-drive motor extend to the outside of the body and are connected to the pedals.

[0069] This application provides a mid-drive motor with a torque sensor and an electric bicycle thereof. The electric bicycle has a mid-drive motor with a torque sensor, which includes a torque generator, a planar bearing, and a torque sensor. The torque generator and the planar bearing are disposed within the gear frame of the mid-drive motor and sleeved on the outer peripheral wall of the hollow shaft of the mid-drive motor. The torque generator and the hollow shaft are connected by a spline. The torque sensor is disposed within the motor housing of the mid-drive motor. When the hollow shaft rotates relative to the gear frame, the torque generator rotates accordingly, simultaneously pushing the planar bearing to move axially. The torque sensor senses the displacement signal of the axial movement of the planar bearing and converts the displacement signal into an electrical signal, which is then sent to the controller of the mid-drive motor. Thus, the planar bearing shaft absorbs the friction damage to the torque sensor caused by the rotation of the torque generator, resulting in a precise and stable signal and increased service life.

[0070] The mid-mounted motor with torque sensor provided by this utility model has the following advantages: the device has a simple structure, light weight, few connections, and good sealing effect.

[0071] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0072] Finally, it should be noted that the above embodiments are merely examples for clearly illustrating the present invention and are not intended to limit the implementation. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A mid-drive motor with a torque sensor, comprising a motor housing, a hollow shaft rotatably disposed within the motor housing, and a gear carrier rotatable with the hollow shaft; characterized in that: It also includes a torque generator, a surface bearing, and a torque sensor; The torque generator and the planar bearing are both disposed within the gear frame of the mid-drive motor and sleeved on the outer peripheral wall of the hollow shaft of the mid-drive motor; the torque generator and the hollow shaft are connected by a spline; the torque sensor is disposed within the motor housing of the mid-drive motor; When the hollow shaft rotates relative to the gear frame, the torque generator generates torque as it rotates, which simultaneously pushes the planar bearing to move axially; the torque sensor senses the displacement signal of the axial movement of the planar bearing and converts the displacement signal into an electrical signal, which is then sent to the controller of the mid-mounted motor.

2. A mid-mounted motor with a torque sensor according to claim 1, characterized in that: The torque generator includes a body, multiple elastic elements, multiple steel balls, and multiple limiting posts; The main body is sleeved on the outer peripheral wall near one end of the hollow shaft, and the main body is splinedly connected to the hollow shaft; the main body is provided with a plurality of first limiting blocks, which are spaced apart circumferentially around the main body; the gear frame is provided with a plurality of second limiting blocks, which are spaced apart circumferentially around the gear frame; the elastic element is disposed between the first limiting blocks and the second limiting blocks; Each of the second limiting blocks is provided with a curved groove, and the main body is provided with a linkage through hole. The steel ball is placed between the curved groove and the linkage through hole. The second limiting block is provided with a limiting post, and the main body is provided with a sliding hole, through which the limiting post passes and can slide relative to the main body; When the hollow shaft drives the body to rotate relative to the gear plate frame, the limiting post and the sliding hole limit the rotation angle, the elastic element is squeezed by the first limiting block and the second limiting block, and the steel ball pushes the planar bearing to move axially under the action of the curved groove.

3. A mid-mounted motor with a torque sensor according to claim 2, characterized in that: The curved groove includes a semi-circular groove and an inclined surface, the inclined surface being disposed on the inner wall of the semi-circular groove on the side away from the limiting post located on the same second limiting block; In the initial state, the steel ball is located within the semi-circular groove; When a torque is generated, the central shaft rotates clockwise, causing the hollow shaft to rotate. The rotation of the hollow shaft causes the body to rotate synchronously. The rotation of the body causes the steel ball to move circumferentially. Under the action of the inclined surface, the steel ball moves axially along the inclined surface. The steel ball passes through the linkage through hole and is pressed on the plane bearing, so that the plane bearing moves axially along the hollow shaft.

4. A mid-mounted motor with a torque sensor according to claim 2, characterized in that: The main body includes a first tube and an annular disk. One end of the first tube is connected to the annular disk. A plurality of first limiting blocks are disposed on the side of the annular disk facing the first tube. The sliding hole and the linkage through hole are both opened on the annular disk. The first tube is splinedly connected to the hollow shaft.

5. A mid-mounted motor with a torque sensor according to claim 4, characterized in that: The gear frame includes a column and multiple fixed gear plates; The first end of the column has a cavity, and the body is housed in the cavity; the second end of the column has a through hole, which communicates with the cavity, and the first tube is rotatably inserted into the through hole. The bottom of the cavity is provided with a receiving groove for accommodating the elastic element, and a plurality of second limiting blocks are disposed in the receiving groove; The plurality of fixed toothed plates are all disposed at the second end of the column, the plurality of fixed toothed plates are spaced apart around the circumference of the column, and the plurality of fixed toothed plates extend outward along the radial direction of the column.

6. A mid-mounted motor with a torque sensor according to claim 5, characterized in that: It also includes an end cap, the end of which forms a limiting step, the end cap being detachably connected to the hollow shaft, and the limiting step and the end cap clamping the body and the gear plate frame.

7. A mid-mounted motor with a torque sensor according to claim 5, characterized in that: The through hole is provided with a wear-resistant ring, and the first tube body is rotatably inserted into the wear-resistant ring.

8. A mid-mounted motor with a torque sensor according to claim 1, characterized in that: The motor housing is provided with a plurality of reset elastic bodies, which are spaced apart circumferentially and abut against the planar bearing; when the torque weakens or disappears, the reset elastic bodies apply a restoring force to the planar bearing, so that the planar bearing moves to the initial position.

9. A mid-mounted motor with a torque sensor according to any one of claims 1 to 8, characterized in that: The torque sensor includes a magnet, a spring plate, a Hall sensor, and an arc-shaped circuit board. The spring plate is inclinedly disposed on the arc-shaped circuit board, one end of the spring plate is connected to one end of the arc-shaped circuit board, and the free end of the spring plate is connected to the magnet. The Hall sensor is disposed on the arc-shaped circuit board, and the arc-shaped circuit board is fixed inside the motor housing. When the planar bearing moves axially along the hollow shaft, the planar bearing presses against the magnet to push the magnet toward the arc-shaped circuit board. The Hall sensor detects the displacement of the magnet and converts the displacement into an electrical signal.

10. An electric bicycle, characterized in that: A mid-mounted motor with a torque sensor as described in any one of claims 1-9.

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