CN219077404U

CN219077404U - Middle shaft transmission mechanism, transmission system and middle motor

Info

Publication number: CN219077404U
Application number: CN202222681226.5U
Authority: CN
Inventors: 徐鹏飞; 王磊; 徐康宁
Original assignee: Dipson Digital Power System Suzhou Co ltd; Kingclean Electric Co Ltd
Current assignee: Kingclean Electric Co Ltd; Lexy Electric Green Energy Technology Suzhou Co Ltd; Suzhou Kingclean Precision Machinery Co Ltd; Jiangsu Kingclean Intelligent Appliance Co Ltd
Priority date: 2022-10-12
Filing date: 2022-10-12
Publication date: 2023-05-26
Anticipated expiration: 2032-10-12

Abstract

The utility model discloses a middle shaft transmission mechanism, a transmission system and a middle motor, wherein the middle shaft transmission mechanism comprises: a center shaft; the moment sensor is fixedly arranged on the center shaft; the dental tray positioning sleeve is connected with the moment sensor through a first isolator; the middle shaft gear is connected to the dental tray positioning sleeve through a second isolator. The middle shaft transmission mechanism provided by the utility model can solve the problem that when the middle motor cannot advance due to power failure, electric quantity exhaustion, transmission failure or manual operation and the like, riding staff can continue riding, and the middle shaft, the tooth disc positioning sleeve and the transmission gear structure of the transmission system are separated from transmission through the second isolator in the riding process, so that the damage of the transmission system can be avoided on one hand, and on the other hand, the riding pressure and the burden of the riding staff can be reduced because any transmission gear of the transmission system is not reversely driven in the riding process to be combined, and the riding at the moment is more labor-saving.

Description

Middle shaft transmission mechanism, transmission system and middle motor

Technical Field

The utility model relates to the field of motor operation, in particular to a center shaft transmission mechanism, a transmission system and a center motor.

Background

The existing centrally-mounted motor has the advantages that the middle shaft gear is used for driving the tooth disc positioning sleeve, the tooth disc on the middle shaft gear is driven to rotate by the tooth disc positioning sleeve, and the tooth disc drives the rear shaft to rotate through the chain. The existing middle shaft gear is fixedly connected with the dental tray positioning sleeve, so that when the middle motor cannot advance in a boosting way due to power failure, electric quantity exhaustion, transmission failure or manual operation (for example, manual operation is performed to close the middle motor or change a boosting mode of the middle motor) and the like, if a rider continues riding, the dental tray positioning sleeve is driven by manpower, the dental tray positioning sleeve rotates to drive the middle shaft gear and the gear meshed with the middle shaft gear to rotate, and the manpower riding is more laborious.

Disclosure of Invention

The technical problems to be solved by the embodiment of the utility model are to provide a middle shaft transmission mechanism, a transmission system and a middle motor, so as to solve the problem that labor is wasted in riding when the middle motor cannot advance in a boosting way due to power failure, electric quantity exhaustion, transmission failure and the like of the middle motor.

In order to solve the technical problems, the present utility model provides a bottom bracket transmission mechanism, comprising:

the middle shaft is used for installing a crank and a pedal to bear riding pedal force;

The moment sensor can be used for detecting the stepping force provided by a rider to the bicycle and is fixedly arranged on the middle shaft;

one end of the tooth disc positioning sleeve is connected with the moment sensor through a first isolator, and the other end of the tooth disc positioning sleeve is fixedly connected with the tooth disc;

the middle shaft gear is connected to the dental tray positioning sleeve through a second isolator;

the dental disk connecting structure is fixedly connected to the dental disk positioning sleeve and is positioned on the outer side of the center shaft gear and used for being connected with the dental disk.

Optionally, the bottom bracket gear includes:

a gear portion;

the support part is correspondingly positioned at the inner side of the gear part in the radial direction and is used for being connected with the dental disc positioning sleeve through a ball bearing;

the transmission part is positioned at one side of the supporting part in the axial direction and is used for being connected with the dental tray positioning sleeve through the second isolator;

wherein, the axis drive mechanism includes helping hand operating mode and non-helping hand operating mode: when the middle shaft transmission mechanism is in a power-assisted working mode, the first isolator and the second isolator are both in a transmission state; when the middle shaft transmission mechanism is in a non-power-assisted working mode, the first isolator and the second isolator are both in a disengaging state.

Optionally, the gear portion, the support portion, and the transmission portion form an L-shaped layout, and the transmission portion is located outside the support portion in an axial direction.

Optionally, the dental tray positioning sleeve is provided with an annular step structure, wherein the first isolator is disposed in the annular step structure, the second isolator is adjacent to the annular step structure, and the outer diameter of the transmission portion does not exceed the outer diameter of the annular step structure.

Optionally, the inside of the dental tray positioning sleeve is connected with the central shaft through two needle bearings, and the two needle bearings are correspondingly positioned at two sides of the supporting part.

Optionally, the two needle bearings are a second needle bearing and a third needle bearing, wherein the second needle bearing is located at the outer side of the third needle bearing, and the third needle bearing is connected to the torque sensor.

Optionally, the inner diameter of the third needle bearing is greater than the inner diameter of the second needle bearing.

Optionally, the torque sensor is fixedly connected with the middle shaft through a spline; the middle shaft is a hollow pipe shaft, and two ends of the middle shaft are respectively connected with a crank.

The utility model also provides a transmission system which comprises a motor assembly, a speed reducing mechanism and the middle shaft transmission mechanism, wherein a first rotating shaft of the motor assembly drives the middle shaft gear to transmit through the speed reducing mechanism.

Optionally, the speed reducing mechanism is a primary speed reducer or a secondary speed reducer.

Optionally, the speed reducing mechanism is a three-stage speed reducer, and the speed reducing mechanism includes:

the primary transmission gear set comprises a primary transmission gear and a primary transmission gear shaft, the primary transmission gear is meshed with the first rotating shaft, and the primary transmission gear shaft is coaxially connected with the primary transmission gear;

the secondary transmission gear set is meshed with the primary transmission gear shaft for transmission;

and the middle shaft gear is meshed with the secondary transmission wheel set for transmission.

Optionally, the first-stage transmission gear shaft includes input, output tooth portion and back shaft, wherein the input with the center inserts is connected, output tooth portion is located the input with between the back shaft, the diameter of back shaft is less than output tooth portion the diameter of input, the back shaft is connected with needle bearing.

Optionally, the outer diameter of the needle bearing is smaller than the tip circle diameter of the output tooth.

Optionally, the secondary transmission wheel set comprises a secondary transmission large gear and a secondary transmission small gear which are coaxially connected, the secondary transmission large gear is meshed with the primary transmission gear shaft, and the secondary transmission small gear is meshed with the middle shaft gear; the secondary transmission pinion is positioned at one side far away from the primary transmission gear shaft, so that the secondary transmission pinion corresponds to the needle bearing in the radial direction.

The utility model also provides a centrally-mounted motor which comprises a shell, the middle shaft transmission mechanism or the transmission system, wherein the middle shaft transmission mechanism or the transmission system is arranged in the shell.

The implementation of the utility model has the following beneficial effects:

the middle shaft transmission mechanism provided by the embodiment can solve the problem that when the middle motor cannot advance due to power failure, electric quantity exhaustion, transmission failure or manual operation and the like, riding staff can continue riding, and the middle shaft, the tooth disc positioning sleeve and the transmission gear structure of the transmission system are separated from transmission through the second isolator in the riding process, so that the damage of the transmission system can be avoided on the one hand, and on the other hand, the riding pressure and the burden of the riding staff can be reduced because any transmission gear of the transmission system is not reversely driven in the riding process to be combined, and the riding at the moment is more labor-saving.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the application and together with the description, serve to explain the principles of the application and do not constitute an undue limitation on the application.

Fig. 1 is a schematic structural view of a rotor core according to an embodiment of the present utility model;

FIG. 2 is an enlarged schematic view of a portion of FIG. 1 at A;

fig. 3 is a schematic structural view of an open structure core sheet according to an embodiment of the present utility model;

fig. 4 is a schematic perspective view of an open structure core sheet according to an embodiment of the present utility model;

fig. 5 is a schematic structural view of a closed-structure core sheet according to an embodiment of the present utility model;

fig. 6 is a schematic perspective view of a closed structure core sheet according to an embodiment of the present utility model;

fig. 7 is a schematic structural view of an open structure core sheet according to an embodiment of the present utility model;

FIG. 8 is a schematic diagram of a rotor in an embodiment of the present utility model;

FIG. 9 is a schematic cross-sectional view of a rotor in an embodiment of the utility model;

FIG. 10 is a schematic diagram of the assembly of a rotor in an embodiment of the utility model;

FIG. 11 is an assembled schematic view of a rotor in an embodiment of the utility model;

FIG. 12 is a schematic diagram of a rotor in an embodiment of the utility model;

FIG. 13 is a schematic view of a primary drive wheel set in accordance with an embodiment of the present utility model;

FIG. 14 is a schematic cross-sectional view of a primary drive wheel set in accordance with an embodiment of the present utility model;

FIG. 15 is a schematic view of a primary drive gear in accordance with an embodiment of the present utility model;

FIG. 16 is a schematic cross-sectional view of a primary drive gear in accordance with an embodiment of the utility model;

FIG. 17 is a schematic view of the structure of a center insert in an embodiment of the present utility model;

FIG. 18 is a schematic view of the structure of a primary drive gear shaft in an embodiment of the utility model;

FIG. 19 is a schematic view of an assembled structure of a secondary drive wheel set in an embodiment of the utility model;

FIG. 20 is a schematic view of a bottom bracket drive mechanism in accordance with an embodiment of the present utility model;

FIG. 21 is a schematic cross-sectional view of a bottom bracket drive mechanism in accordance with an embodiment of the utility model;

FIG. 22 is a schematic view of a bottom bracket gear in accordance with an embodiment of the present utility model;

FIG. 23 is a schematic cross-sectional view of a bottom bracket gear in an embodiment of the utility model;

FIG. 24 is a schematic view of a portion of a transmission system in accordance with an embodiment of the utility model;

FIG. 25 is a schematic view of a portion of a transmission system in accordance with an embodiment of the utility model;

FIG. 26 is a schematic illustration of a portion of a transmission system in accordance with an embodiment of the present utility model;

FIG. 27 is a schematic view of a center motor in an embodiment of the utility model;

FIG. 28 is a cross-sectional view taken along section A-A of FIG. 27 in accordance with an embodiment of the present utility model;

FIG. 29 is a schematic cross-sectional view of a center motor in accordance with an embodiment of the utility model;

FIG. 30 is a schematic view showing the structure of a second rotary shaft (2300A) according to the embodiment of the utility model;

FIG. 31 is a schematic cross-sectional view of a center motor in accordance with an embodiment of the present utility model;

FIG. 32 is a schematic diagram of an assembled structure of a center motor according to an embodiment of the present utility model;

FIG. 33 is a schematic view showing the structure of a third rotary shaft (2300B) according to the embodiment of the utility model;

FIG. 34 is a schematic cross-sectional view of a center motor in an embodiment of the utility model;

FIG. 35 is a schematic perspective view of a center motor in accordance with an embodiment of the present utility model;

fig. 36 is a schematic view of a mounting structure of a main cover and a resolver thereof according to an embodiment of the present utility model.

Reference numerals in the drawings: 1000-a main housing; 1001-a motor installation cavity; 1002-a spin-on mounting cavity; 1003-transmission cavity;

1010-a stator mounting portion; 1011-an annular groove;

1020-separator; 1022-a second bearing mounting chamber; 1023-a second ball bearing;

1030-heat sink ribs;

1100-motor cover; 1110-a first bearing mounting chamber; 1111—a first ball bearing;

1200-transition shell;

1210-shaft hole;

1220-annular ribs; 1230-a fixed block; 1240-bearing mounting chamber;

1300-a main machine cover;

2000-motor assembly;

2100-stator;

2200-rotor core;

2210-core stamping; 2211-notch; 2212-shaft hole; 2213-core yoke; 2214-core teeth;

2215-a magnetic steel installation groove; 2216-pole piece; 2217-magnetic shielding strips; 2218-a round hole; 2219-a support block;

2220—spindle mounting hole;

2210A-iron core punching sheet with an opening structure; 2210B-iron core punching sheet with closed structure;

2300—a first shaft; 2300A-a second shaft; 2300B-a third shaft;

2310-shaft-shaped portion;

2320-tooth; 2321-engagement region; 2322-non-engagement region; 2323-a separator tank; 2324-grooves; 2345-induction magnetic steel; 2346-internal taper;

2340-rotor connection;

2350-power take-off;

2360-a spin-on mounting end; 2361-a third securing structure;

2370-rotor connection end;

2380-a power take-off;

3000-resolver;

3100-swirl stator; 3120-annular grooves;

3200-a rotor;

4000-first-stage transmission wheel sets;

4100—a primary drive gear;

4110-outer ring teeth;

4120-center insert; 4121-reinforcing teeth;

4200—primary drive gear shaft;

4210-input terminal;

4220-output teeth;

4230-a support shaft;

4240-a first needle bearing;

5000-two-stage transmission wheel sets;

5100-two-stage transmission big gear;

5200-a secondary drive pinion;

6000-middle shaft transmission mechanism;

6001-a second needle bearing; 6002-third needle bearings; 6003-a third ball bearing;

6100-center axis;

6200-dental tray positioning sleeve; 6210-annular step structure;

6300-moment sensor;

6400-bottom bracket gear; 6410-a gear portion; 6420-a support; 6430-a transmission;

6500-first isolator;

6600-a second isolator;

6700-dental tray connection;

7100-wiring boards; 7110-sensing elements;

7200-bearing support.

Detailed Description

In order that the above objects, features and advantages of the utility model will be readily understood, a more particular description of the utility model will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model. The present utility model may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the utility model, whereby the utility model is not limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this utility model belongs. The terminology used herein in the description of the utility model is for the purpose of describing particular embodiments only and is not intended to be limiting of the utility model. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

In the prior art, the notches of all the core punched sheets 2210 are overlapped, and through grooves which are axially arranged and penetrate through two ends of the rotor core are formed in the rotating shaft mounting hole 2220 after lamination forming. Because the iron core punching 2210 is formed by stamping with the same die, if the stamping deformation of one notch is different from that of other notches in the stamping process of the die, after the iron core punching sheets are laminated, the through slots formed by the notches at the same position are different from the holding force of other through slots on the rotating shaft, so that the whole rotor iron core is easy to jump.

As shown in fig. 1-7, the present embodiment provides a rotor core, including a plurality of groups of core sheets, each group of core sheets includes at least one core sheet 2210, the number of core poles of the core sheet 2210 is N (N is an even number greater than 2), M notches 2211 are disposed in a shaft hole 2212 of the core sheet 2210, M is not an integer multiple of N, and after the plurality of groups of core sheets 2210 are laminated to form the rotor core, projections of the notches 2211 of at least one group of core sheets and the notches 2211 of other groups of core sheets on a plane where any core sheet 2210 is located are not overlapped (or at least partially staggered). In this embodiment, the notches 2211 are formed in the shaft hole 2212 of the core punching sheet 2210, so that the notches 2211 can be staggered in the axial direction of the rotating shaft and connected with the rotating shaft in an interference fit manner after being laminated and formed, notch defects caused by process reasons can be uniformly distributed in the circumferential direction of the rotating shaft, and notch concentration of the defects is avoided.

According to the rotor core, the notch is arranged on the shaft hole, and the notch is arranged in a staggered mode during lamination forming, so that the problem of jumping after the rotating shaft is pressed into the rotor core due to the notch is reduced or eliminated after the rotor core is formed.

The angular difference between two adjacent groups of core segments 2210 is K (i.e., the adjacent groups of core segments are stacked again after rotating by an angle K), where k=360×n/N, N being a natural number less than N; the rotation angle difference K is not equal to 360 x M/M (so as to avoid overlapping between different notches after rotating by the rotation angle K), M is a natural number smaller than M, so that the notches 2211 of the multiple groups of core punching sheets are spirally arranged on the rotating shaft mounting hole 2220 of the rotor core.

Generally, the number of notches M should be much smaller than the number of poles N of the core, so as to reduce the number of openings of the notches and provide a sufficiently large contact area between the core sheet and the rotating shaft.

Further, when the iron core punching sheet is laminated and rotated in a rotary mode, the defect that the single-side dynamic balance amount is overlarge due to single-side deviation of the iron core punching sheet in the iron core punching process can be overcome, and the single-side deviation iron core punching sheet is uniformly distributed on the circumference, so that the dynamic balance amount of the iron core in the circumferential direction is kept consistent, and the debugging time of dynamic balance of a production line is saved.

Particularly, when one side of the iron core is larger or smaller due to punching, if the iron core is directly overlapped, the whole rotor iron core is single-side offset, and the single-side dynamic balance quantity is overlarge, so that the dynamic balance quantity is enlarged. The rotary laminating method can ensure that each iron core punching sheet forms a certain included angle with the previous iron core punching sheet, the part with poor size can also deviate, and after one or more circles of rotation, the part with poor size can be uniformly distributed on the circumference.

Alternatively, the number of M may be plural, and the M notches are uniformly distributed at the edge of the shaft hole 2212, so that when the core punching sheet is in interference fit with the rotating shaft, the contact area between each position of the shaft hole of the core punching sheet and the rotating shaft is equal, and the stress in each direction is also equal.

The spiral shape includes at least 1 circumference, so that the notches 2211 can be uniformly distributed over the circumference of the rotating shaft, and the notches 2211 are uniformly stressed in all directions;

the spiral shape is an integer number of circumferences, i.e., 1, 2 or more circumferences, so that the notches 2211 can be uniformly distributed over the circumference of the entire rotation shaft, and the notches 2211 are uniformly stressed in all directions.

The notch 2211 is triangular, arc-shaped, semicircular, rectangular or trapezoidal, the notch 2211 may be any combination of the above shapes, or the notch 2211 may be other non-illustrated special-shaped shapes. To reduce stress concentrations caused by the notch 2211, the notch may be designed with a rounded transition structure.

As shown in fig. 3 and 7, the core segment 2210A includes a core yoke 2213 and core teeth 2214 arranged in a circumferential array around the core yoke 2213, two ends of an outer edge of each core tooth 2214 are respectively provided with pole shoes 2216 extending to two sides, and a magnetic steel mounting groove 2215 is formed between two adjacent core teeth 2214; the core tooth 2214 has a fan-shaped structure with a radius R1 smaller than the radius R of the core sheet. The circle centers of the fan-shaped structures of all the iron core teeth 2214 are on the same circle with the axle center of the rotor iron core as the circle center, the radius is R2, and the r=r1+r2 is satisfied. Specifically, the arrangement direction of each fan-shaped structure points to the outside along the direction of the connecting line of the center of the core segment 2210 and the center of the core tooth 2214; and the midpoints of the arcs of the fan-shaped structure are located on the outer circle of the core segment 2210 at the same time. The core tooth 2214 of the core punching sheet is designed into an eccentric circle structure relative to the center of the whole core punching sheet, so that the waveform can be ensured to be closer to a sine wave, and the harmonic wave is reduced.

The iron core tooth 2214 is connected with the iron core yoke 2213 through the magnetism isolating strip 2217, the width of the magnetism isolating strip 2217 is smaller than the minimum width of the iron core tooth 2214, and the magnetism isolating strip can effectively reduce magnetism leakage.

The sector surface of the iron core tooth 2214 is provided with a round hole 2218, the three sides of the round hole 2218 are equal to the three sides of the sector surface, and the magnetic density can be guaranteed to be uniform through the structural design of the round hole 2218.

The core segments 2210 include an open structure core segment 2210A and a closed structure core segment 2210B, wherein the open structure core segment 2210A is disposed between the closed structure core segments 2210B; wherein, the core punching sheet 2210B with a closed structure is connected with the pole shoes 2216 of two adjacent core teeth 2214 to form a closed structure. Through the interval structure design of the closed structure iron core punched sheet 2210B and the open structure iron core punched sheet 2210A, the structural strength of the whole rotor iron core can be increased. As shown in fig. 1-2, the core punched pieces 2210B with a closed structure are arranged at two ends and in the middle of the whole rotor core in a 2-piece combination mode; the core segments 2210A with the open structure are arranged between the core segments 2210B with the closed structure in a 14-segment combination mode. In the specific implementation process, the usage ratio of the open-structure core segment 2210A and the closed-structure core segment 2210B is not limited thereto, and may be increased or decreased according to implementation needs by those skilled in the art.

The core yoke 2213 between two adjacent magnetic isolation strips 2217 is further provided with a support block 2219 for positioning the short sides of the magnetic steel, and for reducing magnetic leakage. The supporting block 2219 can play a role in positioning and fixing the magnetic steel. Specifically, after the magnetic steel is pressed into the magnetic steel mounting groove 2215, the supporting block 2219 deforms to a certain extent so as to prop against the side surface of the magnetic steel, so that the magnetic steel and the magnetic steel mounting groove 2215 form interference fit in the radial direction, and the magnetic steel is tightly propped against the convex edge or the limiting structure on the outer side of the magnetic steel mounting groove 2215, so that unbalance change caused by magnetic steel displacement and vibration noise generated by the unbalance change are effectively reduced.

Due to the design of the spacing structure of the closed-structure core lamination 2210B and the open-structure core lamination 2210A, the support blocks 2219 are periodically arranged on the radial inner side surface of the magnetic steel mounting groove 2215 of the rotor core formed after the closed-structure core lamination 2210B and the open-structure core lamination 2210A are alternately stacked. That is, on any one of the core segments 2210, the support blocks 2219 are periodically distributed with respect to the center of the core segment 2210. After the plurality of core segments 2210 are stacked to form the rotor core, the supporting blocks 2219 are distributed at intervals in the axial direction of the whole rotor core, and in any one of the magnetic steel mounting grooves 2215, the supporting blocks 2219 are arranged on the core segments 2210B with a closed structure.

As shown in fig. 8 to 12, the present embodiment also provides a rotor including the first rotor 2300 and the rotor core 2200 provided in the above embodiment, the first rotor 2300 being coupled in the rotor mounting hole 2220 of the rotor core 2200 by interference fit. The first shaft 2300 in this embodiment may be a conventional rotor output shaft (i.e., the output end of the shaft is also shaft-shaped), or may be a rotor tooth shaft (i.e., tooth surface is machined at the output end of the shaft to mesh with a gear).

According to the rotor provided by the utility model, the first rotating shaft 2300 is connected with the rotor core 2200 in an interference fit mode, and the problem of jumping after the rotating shaft is pressed into the rotor core due to the fact that the positions of the notches are consistent is reduced or eliminated through the notch arrangement mode of the core punching 2210 on the rotor core 2200.

Further, when the iron core punching sheets are laminated in a rotary mode, the defect that the single-side dynamic balance amount is too large due to single-side deviation of the iron core punching sheets in the iron core punching process can be overcome, and the single-side deviation iron core punching sheets are uniformly distributed on the circumference, so that the dynamic balance amount of the iron core in the circumferential direction is kept consistent, and the debugging time of the dynamic balance of a production line is saved.

Alternatively, in this embodiment, when first shaft 2300 is a rotor tooth shaft, first shaft 2300 includes shaft-shaped portion 2310 and tooth-shaped portion 2320, and shaft-shaped portion 2310 is connected to rotor core 2200 by interference fit; the tooth surface extending to the end is machined on the surface of the tooth-shaped portion 2320, the tooth-shaped portion 2320 comprises a meshing area 2321 and a non-meshing area 2322, the meshing area 2321 is connected with the shaft-shaped portion 2310, the meshing area 2321 is used for meshing with a transmission gear so as to output power of a rotor, the non-meshing area 2322 is located at the free end of the first rotating shaft 2300, a circular cutting partition groove 2323 is formed in the tooth surface at the juncture of the meshing area 2321 and the non-meshing area 2322, and the tooth surface can be of a helical tooth or a straight tooth. By the design of the isolation groove 2323, when the tooth-shaped portion 2310 of the first rotor 2300 is pressed into the rotor shaft mounting hole 2220 of the rotor core 2200, the non-engagement region 2322 bears impact force, so that deformation generated by the tooth surface is not conducted to the engagement region 2321, and the tooth shape of the engagement region 2321 is ensured to be unchanged. Those skilled in the art will appreciate that the break groove 2323 may also be disposed in the non-engagement region 2322, so that a portion of the non-engagement region remains outside of the engagement region 2321, and is better engaged with the transmission gear.

When the first shaft 2300 is pressed into the shaft mounting hole 2220 of the rotor core 2200 provided in the above embodiment, since the notches 2211 of the core punches 2210 of the rotor core 2200 are arranged in a staggered manner, the pressing force between the first shaft 2300 and the shaft mounting hole 2220 is larger, and thus, the design of the partition groove 2323 is adopted for the first shaft 2300, so that the tooth shape of the engagement area 2321 can be better ensured to be unchanged. Because the rotor core dislocation notch scheme of the embodiment leads to a larger press-in area (the notch part is not contacted with the rotating shaft when the traditional rotor core is pressed in), the press-in force of the first rotating shaft 2300 is larger when the rotor core is pressed in, and the change of the tooth profile of the end part of the first rotating shaft 2300 is necessarily larger when the press-in force is applied to the end part of the first rotating shaft 2300; by adopting the structural design of the partition groove 2323 in this embodiment, the pressing force borne by the tooth surface at the inner side of the partition groove 2323 is smaller or the transmission of the pressing force at the tooth surface can be completely blocked, so that the tooth surface is enabled to be deformed less or not to be deformed in the process of pressing the first rotation shaft 2300 into the rotor core.

As can be appreciated by those skilled in the art, when the structure of the rotor core 2200 and the structure design of the partition slot 2323 provided in the above embodiment are used simultaneously, the partition slot 2323 can greatly reduce the deformation influence on the tooth surface when the first rotor shaft 2300 is pressed into the structure of the rotor core 2200, so that the effect on improving the pressing force caused by the rotor core 2200 with staggered notches is better; however, when rotor core 2200 is of a conventional structure (notches are arranged linearly along the axial direction), the influence of the pressing force on the deformation of the tooth surface can be effectively reduced.

The depth of the partition groove 2323 does not exceed the height of the tooth surface so that the first shaft 2300 can have good mechanical strength at the tooth-shaped portion 2320, and if the depth of the partition groove 2323 exceeds the height of the tooth surface, the depth of the partition groove 2323 is deep into the inside of the root circle. Therefore, the bottom surface of the partition groove 2323 should be higher than the circumference where the root circle is located, and preferably, the depth of the partition groove may be less than half of the tooth surface height, so that on one hand, the pressing force to the first rotation shaft 2300 is ensured to be better transmitted to the shaft 2310, and on the other hand, the tooth surface deformation caused during the transmission process may be minimized.

The length between the partition groove 2323 and the end of the first shaft 2300 is not more than one third of the tooth surface length, so that the structural layout design of the first shaft 2300 can be more optimized.

Alternatively, as shown in fig. 11, a groove 2324 is formed on an end face of the first shaft 2300 at one end of the shaft portion 2310, and a sensing magnetic steel 2345 is installed in the groove 2324, so that the sensing magnetic steel 2345 is arranged in the groove 2324, and the structure of the first shaft 2300 can be more reasonably utilized, so that on one hand, the pressing force on the first shaft 2300 can be better conducted to the shaft portion 2310, on the other hand, the tooth surface deformation caused in the conducting process can be reduced to the greatest extent, and on the other hand, the fixing of the sensing magnetic steel 2345 can be realized.

When the groove 2324 is formed on the end face of the first rotation shaft 2300, the stress area of the end face of the first rotation shaft 2300 is greatly reduced, so that the deformation influence on the tooth surface is larger when the pressing force acts on the end face of the first rotation shaft 2300, and the conventional tooth surface is continuous, so that the tooth surface of the engagement part is also deformed due to the continuous transmission of the tooth surface deformation, and the engagement abrasion of the whole rotation shaft in the process of engagement with the transmission gear is increased; again, the design of the partition slot 2323 may better address this technical issue.

The groove 2324 is circular, an inner conical surface 2346 is arranged in the center of the groove 2324, correspondingly, the induction magnetic steel 2345 is also circular, and the shape of the induction magnetic steel 2345 is matched with that of the groove 2324, so that the induction magnetic steel 2345 can be installed in the groove 2324. At this time, the depth of the groove 2324 should be greater than or equal to the height of the induction magnetic steel 2345, so that the induction magnetic steel 2345 can be embedded inside the groove 2324 after the induction magnetic steel 2345 is installed in the groove 2324, so as to avoid the exposure of the induction magnetic steel 2345, thereby protecting the induction magnetic steel 2345.

The diameter of the groove 2324 is smaller than the diameter of the root circle of the tooth surface, so that the problem that the area of the groove 2324 for transmitting the pressing force inside the root circle is too small due to the fact that the groove 2324 is too large is avoided, and the protection effect on the induction magnetic steel 2345 after the induction magnetic steel 2345 is installed can be guaranteed.

The sensing magnetic steel 2345 is also circular, and the diameter of the sensing magnetic steel 2345 is slightly larger than that of the groove 2324, so that the sensing magnetic steel 2345 is installed in the groove 2324 in an interference fit mode; alternatively, one skilled in the art may alternatively couple the sensing magnet steel 2345 in the groove 2324 by a glue.

When the induction magnetic steel 2345 is connected in the groove 2324 in an interference fit manner, a tooth surface around the groove is necessarily deformed; therefore, the design of the partition groove 2323 in the technical scheme of the present utility model can perfectly solve the problem that the tooth surface deformation is transferred to the engagement region 2321, thereby ensuring that the tooth shape of the engagement region 2321 is unchanged and the service life of the first rotation shaft 2300.

The embodiment also provides a method for forming the rotor core, which comprises the following steps:

providing and grouping iron core sheets 2210, wherein each group of iron core sheets comprises at least one iron core sheet 2210, and the circumference of a shaft hole of at least one iron core sheet 2210 in each group of iron core sheets is provided with a notch 2211;

the core segments 2210 are stacked to form the rotor core 2200, such that a deflection angle of 360 x N/N is provided between the notches of two adjacent groups of core segments 2210, where N is a natural number less than N.

According to the rotor core forming method provided by the utility model, the notches 2211 are formed on the rotating shaft mounting hole 2220 in a spiral mode through lamination forming in a rotating mode, and the notches 2211 are uniformly distributed on the circumference, so that the defect that the unilateral dynamic balance amount is overlarge due to unilateral deflection of the iron core sheet in the punching process of the iron core sheet 2210 can be overcome, the unilateral deflected iron core sheet 2210 is uniformly distributed on the circumference, the dynamic balance amount of the iron core in the circumferential direction is kept consistent, and the debugging time of dynamic balance of a production line is saved.

When the number of the notches M is multiple, the notches are uniformly distributed around the shaft hole of the iron core punching sheet, and deflection angles 360 x N/N are not equal to 360 x M/M (M is a natural number smaller than M), so that the notches form M spiral shapes in the rotating shaft mounting hole.

The present embodiment also provides a rotor including a first rotor 2300 and a rotor core 2200 manufactured by the molding method provided in the above embodiment, the first rotor 2300 being coupled in a shaft mounting hole 2220 of the rotor core 2200 by interference fit.

According to the rotor provided by the utility model, the gap 2211 is arranged on the shaft hole of the iron core punched sheet 2210, and the gaps are arranged in a staggered manner when the iron core punched sheet is laminated and formed, so that the rotor jumping problem caused by that the rotating shaft is pressed into the rotor core 2200 due to the gaps is reduced or eliminated after the rotor core is formed.

The present embodiment also provides an electric motor including the rotor core provided by the above embodiment or the rotor provided by the above embodiment.

The embodiment also provides a centrally-mounted motor, which comprises the rotor core provided by the embodiment or the rotor provided by the embodiment.

According to the motor and the centrally-mounted motor provided by the utility model, due to the fact that the rotor core 2200 with the gaps arranged in a staggered manner is used, the jumping problem of a rotating shaft pressed into the rotor core due to the fact that the positions of the gaps are consistent is reduced or eliminated, the motor and the centrally-mounted motor rotate more stably, the pressing force is greatly reduced or even completely eliminated due to the design of the partition grooves 2323, and meanwhile, the problems that the stress area of the end face of the rotating shaft is reduced due to the grooves 2324 and the tooth face is deformed due to the fact that the inductive magnetic steel 2345 connected in an interference fit mode is used are overcome.

Referring to fig. 25, the embodiment of the present utility model further provides a detection system, which includes a circuit board 7100, an inductive element 7110, and the first shaft 2300 provided in the foregoing embodiment, in which a tooth surface of the first shaft 2300 is provided with a partition groove 2323, a groove 2324 is formed on an end surface of the first shaft 2300, an inductive magnetic steel 2345 is disposed in the groove 2324, a position of the inductive element 7110 corresponds to a position of the inductive magnetic steel 2345, the inductive element 7110 is connected to the circuit board 7100, and an inductive signal is sent to the circuit board 7100.

The detection system provided in this embodiment can overcome the deformation of the rotating shaft and the tooth surface caused by the concentrated pressing force of the end face of the first rotating shaft 2300 due to the installation of the induction magnetic steel 2345, so that the position between the induction magnetic steel 2345 and the induction element 7110 is more accurate, and the detection effect of the detection system is better.

In this embodiment, the center of the sensing element 7110 and the sensing magnetic steel 2345 are located on the same axis, so that the sensing element 7110 has better detection effect on the sensing magnetic steel 2345.

In this embodiment, the sensing element 7110 is a magnetic braid chip. It will be appreciated by those skilled in the art that other elements capable of performing the same function as the magnetic braid chip may be used for inductive element 7110.

With reference to fig. 24-26, this embodiment further provides a centrally-mounted motor drive system, including a primary drive pulley set 4000 and the first shaft 2300 provided in the above embodiment, where the primary drive pulley set 4000 includes a primary drive gear 4100, and the primary drive gear 4100 is engaged with the engagement area 2321 of the first shaft 2300. In the transmission system provided in this embodiment, the partition groove 2323 is provided on the first shaft 2300, so that after the first shaft 2300 is pressed into the rotor core 2200, the tooth surface of the engagement area 2321 on the first shaft 2300 cannot deform or greatly reduce the deformation amplitude due to the pressing force, so that the transmission effect between the engagement area 2321 of the transmission shaft 2300 and the primary transmission gear 4100 is better in the process of meshing transmission, and the mutual meshing damage caused by the deformation of the tooth surface is avoided, thereby ensuring the transmission effect and the service lives of the first shaft 2300 and the primary transmission gear 4100.

Referring to fig. 13-17, in the transmission system provided in this embodiment, the primary transmission gear 4100 includes a center insert 4120 and an outer ring gear portion 4110, the center of the center insert 4120 has a shaft hole, the outer ring gear portion 4110 is connected to the outer circumference of the center insert 4120 and is coaxially arranged, the outer ring gear portion 4110 has a width in the axial direction larger than that of the center insert 4120, and both ends of the outer ring gear portion 4110 in the axial direction exceed the center insert 4120; the center insert 4120 is made of a metal material, and the outer ring gear portion 4110 is made of a non-metal material. In the transmission system provided in this embodiment, the first rotation shaft 2300 is adopted to directly drive the primary transmission gear 4100, so that the rotation speed of the first rotation shaft 2300 is high, the primary transmission gear 4100 made of an integral metal material has large moment of inertia, and energy loss is caused; the first-stage transmission gear 4100 made of non-metal materials has the problems that the contact surface stress is large and the supporting strength can not meet the transmission requirement; therefore, the central insert 4120 made of metal material and the outer ring gear 4110 made of non-metal material are adopted in the present embodiment, and the width of the outer ring gear 4110 is made larger than that of the central insert 4120, so that on one hand, a larger contact area between the outer ring gear 4110 and the first rotation shaft 2300 is ensured, the contact stress of the outer ring gear 4110 is reduced, on the other hand, the rotational inertia of the central insert 4120 and the outer ring gear 4110 is lower, the energy loss in the transmission process is reduced, and on the other hand, the requirement of transmission torque can be met due to the smaller size of the central insert 4120 made of metal material.

Referring to fig. 17, in the transmission system provided in the present embodiment, the outer circumferential surface of the center insert 4120 is provided with a reinforcing structure; the reinforcing structure protrudes or is recessed from the surface of the outer circumference. The design of the reinforcing structure can effectively increase the connection area between the center insert 4120 and the outer ring tooth part 4110, so that the combination between the center insert 4120 and the exchange part 4110 is more stable, and the overall shape can be kept unchanged in the transmission process; particularly in the case of a reduced width of the center insert 4120, the problem of reduced connection area can be compensated for by the reinforcing structure.

In the transmission system provided by this embodiment, the reinforcing structure is a reinforcing tooth 4121, knurl or spline disposed around the outer circumference of the center insert 4120.

In the transmission system provided in the present embodiment, the reinforcing teeth 4121 are divided into at least three segments in the axial direction. The design can make the outer ring gear 4110 not only further increase the connection area with the center insert 4120, but also overcome the axial stress in the transmission process, and keep the center insert 4120 and the outer ring gear 4110 stable in structure in the transmission process.

The tooth top surface of the reinforcing tooth 4121 is a cambered surface or a surface with an obtuse angle. In this embodiment, the protruding top portion cannot be made into a sharp corner, and the width of the top portion is not less than 0.2mm, so that stress concentration during injection molding is avoided, and the sharp corner end is broken when bearing a large torque.

In the transmission system provided in this embodiment, when the splines are adopted between the center insert 4120 and the outer ring gear portion 4110, the number of the splines is not less than 4, and the spline modulus is not less than 0.25.

In the transmission system provided in this embodiment, the outer ring gear portion 4110 is injection molded on the outer circumference of the center insert 4120, so that the connection between the center insert 4120 and the outer ring gear portion 4110 is tighter, and thus the outer ring gear portion 4110 is not easy to deform in the transmission process.

Referring to fig. 13-17, in the transmission system provided in this embodiment, the primary transmission gear set 4000 further includes a primary transmission gear shaft 4200, and the primary transmission gear shaft 4200 is coaxially connected with the primary transmission gear 4100.

Referring to fig. 18 and 28, in the transmission system provided in this embodiment, the primary transmission gear shaft 4200 includes an input end 4210, an output gear portion 4220 and a support shaft 4230, wherein the input end 4210 is connected with the center insert 4120, the output gear portion 4220 is located between the input end 4210 and the support shaft 4230, the diameter of the support shaft 4230 is smaller than the diameters of the output gear portion 4220 and the input end 4210, the support shaft 4230 is connected with the first needle bearing 4240, and the outer diameter of the first needle bearing 4240 is smaller than the tip circle diameter of the output gear portion 4220. In the transmission system provided by the embodiment, the supporting shaft 4230 is designed at the end part of the primary transmission gear shaft 4200, the supporting shaft 4230 is smaller in diameter, the needle bearing with relatively smaller diameter is connected to the supporting shaft 4230, and the transmission end of the primary transmission gear shaft 4200 is supported by the needle bearing, so that the problem of serious unilateral abrasion of the primary transmission gear shaft 4200 in the transmission process due to the suspension state is solved, the transmission stability of the transmission system is ensured, and the unilateral abrasion of the primary transmission gear shaft in the transmission process is reduced.

In the transmission system provided in this embodiment, as shown in fig. 18, the input end 4210 is connected with the center insert 4120 through splines disposed on the surface of the input end 4210, so that the circumferential binding force between the center insert 4120 and the outer ring gear portion 4110 is more uniform, and the coaxiality is also better. It will be appreciated by those skilled in the art that a spline connection may be used instead of a keyway.

In the transmission system provided in this embodiment, in conjunction with fig. 14 and 18, bearings are respectively disposed on the input ends 4210 on both sides of the center insert 4120, and the bearings are at least partially located inside the outer ring gear portion 4110. At this time, the outer diameter of the bearing should be smaller than the inner diameter of the outer ring gear 4110, and the arrangement of the two sides of the center insert 4120 can make the center insert 4120 support the outer ring gear 4110 more stable, and at the same time, the bearing is matched with the needle bearing on the support shaft 4230, so that both ends and the middle of the entire primary transmission gear shaft 4200 can be well supported, and the problem of unilateral abrasion caused by suspension of the primary transmission gear shaft 4200 in the transmission process is avoided. By adopting the overall structure layout of the outer ring gear 4110, the central insert 4120 and the bearings at the two sides, the transmission space can be more reasonably utilized, the transmission stability is ensured, and the service life of the primary transmission gear shaft 4200 can be prolonged.

As shown in fig. 24, the transmission system provided in this embodiment further includes a secondary transmission gear set 5000 and a central shaft transmission mechanism 6000, wherein the secondary transmission gear set 5000 includes a secondary transmission large gear 5100 and a secondary transmission small gear 5200 which are coaxially connected, the secondary transmission large gear 5100 is meshed with the primary transmission gear shaft 4200, and the secondary transmission small gear 5200 is meshed with the central shaft transmission mechanism 6000. The transmission system provided by the embodiment transmits power to the middle shaft in a three-stage transmission mode.

As shown in fig. 20 and 21, in the transmission system provided in this embodiment,

the bottom bracket transmission 6000 comprises a bottom bracket 6100, a moment sensor 6300, a tooth disc positioning sleeve 6200, a bottom bracket gear 6400, a first isolator 6500, a second isolator 6600 and the like, wherein:

the middle shaft 6100 is used for installing a crank and a pedal to bear riding pedal force, the two ends of the middle shaft are respectively connected with the crank and the pedal, and the middle shaft can receive power input through a crank structure at the two ends and transmit the power input to the dental disc positioning sleeve 6200 through the torque sensor 6300 so as to transmit the power to a dental disc on the dental disc positioning sleeve 6200, so that the rear shaft is driven to rotate so as to drive the bicycle to advance;

the torque sensor 6300 can be used for detecting the stepping force provided by a rider for a bicycle, and is fixedly arranged on the middle shaft 6100, the torque sensor 6300 can sense a torque signal transmitted by the middle shaft 6100 to the dental disc positioning sleeve 6200 and transmit the torque signal to the controller, and the controller controls the output power of the motor assembly 2000 in the middle motor according to the magnitude of the sensed signal;

The tooth disc positioning sleeve 6200, one end of which is connected with the moment sensor through the first isolator 6500, the other end of which is fixedly connected with the tooth disc, and the clutch transmission effect between the tooth disc positioning sleeve 6200 and the moment sensor 6300 is realized through the first isolator 6500, so that when the middle shaft 6100 stops rotating due to the control of a riding person, the middle shaft 6100 is prevented from continuing to rotate due to the fact that the transmission system of the middle motor continues to rotate due to the rotation inertia, and the safety of the riding person is protected;

the middle shaft gear 6400 is connected to the dental tray positioning sleeve through a second isolator 6600; and the middle shaft gear 6400 is meshed with the secondary transmission pinion 5200, the clutch transmission effect between the dental tray positioning sleeve 6200 and the middle shaft gear 6400 can be realized through the second isolator 6600, when the middle motor cannot advance in a boosting way due to power failure, electric quantity exhaustion, transmission failure or manual operation (such as manual operation of closing the middle motor or changing a boosting mode of the middle motor) and the like, a rider can continue riding, and the middle shaft 6100, the dental tray positioning sleeve 6200 and the transmission gear structure of the transmission system are separated from transmission through the second isolator 6600 in the riding process, so that the damage of the transmission system can be avoided, and on the other hand, the riding pressure and the burden of the rider can be reduced because any transmission gear combination of the transmission system is not reversely driven in the riding process, and the riding at the moment is more labor-saving.

Wherein, the axis drive mechanism includes helping hand operating mode and non-helping hand operating mode: when the middle shaft transmission mechanism is in a power-assisted working mode, the first isolator 6500 and the second isolator 6600 are both in a transmission state; when the bottom bracket drive mechanism is in the non-assist mode of operation, both the first and second one-

way devices

6500, 6600 are in a disengaged state.

Those skilled in the art can know that when the primary transmission wheel set 4000 and the secondary transmission wheel set 5000 are not used in the transmission system, the middle shaft gear 6400 can be directly driven by the motor assembly 2000, that is, when the transmission system provided in the embodiment is adjusted from three-stage transmission to one-stage transmission, the driving of the middle shaft can be realized, and the transmission requirement of the middle motor can be met. Similarly, those skilled in the art may adjust the transmission system provided in this embodiment from three-stage transmission to two-stage transmission or four-stage transmission.

The transmission system provided by the embodiment can solve the problem that when the middle motor cannot advance in a boosting way due to power failure, electric quantity exhaustion, transmission faults or manual operation (such as manual operation of closing the middle motor or changing a boosting mode of the middle motor) and the like, a rider can continue riding, and in the riding process, the middle shaft 6100 and the dental tray positioning sleeve 6200 are separated from a transmission gear structure of the transmission system through the second isolator 6600, so that on one hand, the damage to the transmission system can be avoided, and on the other hand, the riding pressure and the burden of the rider can be reduced because any transmission gear of the transmission system is not reversely driven in the riding process are combined, and the riding at the moment is more labor-saving.

As shown in fig. 22 and 23, in the transmission system provided in this embodiment, the bottom bracket gear includes a gear portion 6410, a supporting portion 6420, and a transmission portion 6430, wherein:

the gear portion 6410 is located on the outer side and is used for meshing transmission with other gears (such as the secondary transmission large gear 5100);

the supporting part 6420 is correspondingly positioned at the inner side of the gear part 6410 in the radial direction and is used for being connected with the dental tray positioning sleeve 6200 through the third ball bearing 6003, and the supporting part 6420 can provide stable support for the gear 6410 and ensure the stable transmission of the gear 6410;

the transmission part 6430 is located at one side of the supporting part 6420 in the axial direction and is used for being connected with the dental tray positioning sleeve 6200 through the second isolator 6600, and the transmission part 6430 realizes clutch transmission of the gear 6410 and the dental tray positioning sleeve 6200 under the action of the second isolator 6600.

The transmission system provided by the embodiment improves the middle shaft gear structure, so that the middle shaft gear structure is obviously different from the conventional gear structure, and the stress function of the supporting part and the transmission function of the transmission part are separated, so that the direct stress supporting transmission of the second isolator is avoided.

Further referring to fig. 21, in the transmission system provided in this embodiment, the gear portion 6410, the supporting portion 6420 and the transmission portion 6430 form an L-shaped layout, and in the axial direction, the transmission portion 6430 is located outside the supporting portion 6420 and is structurally closer to the location of the dental disc connecting structure 6700, and the supporting portion 6420 is closer to the location of the annular step structure 6210 of the dental disc positioning sleeve 6200, so that the structural layout is reasonable, and the power transmission is closer to the location of the dental disc, so that the power transmission is more stable.

The dental disc positioning sleeve 6200 is provided with an annular step structure 6210, wherein the first isolator 6500 is disposed in the annular step structure 6210, the second isolator 6600 is proximate to the annular step structure 6210, and the outer diameter of the transmission portion 6430 does not exceed the outer diameter of the annular step structure 6210; therefore, the overall structure is reasonable and compact in layout and small in occupied space.

The tooth disc positioning sleeve 6200 is internally connected with the central shaft 6100 through two needle bearings, the two needle bearings are correspondingly positioned at two sides of the supporting portion, and the structural size of the needle bearings is smaller, so that the size requirement of the tooth disc positioning sleeve 6200 is reduced, and meanwhile, the two needle bearings are arranged at two sides of the supporting portion 6420, so that a more stable supporting effect can be provided for the supporting portion 6420.

The two needle bearings are a second needle bearing 6001 and a third needle bearing 6002, wherein the second needle bearing 6001 is located outside the third needle bearing 6002, the third needle bearing 6002 is connected to the torque sensor 6300, and correspondingly, the connecting position of the torque sensor 6300 is also set to be in a step shape, so that the structure can be more compact.

The inner diameter of the third needle bearing 6002 is larger than the inner diameter of the second needle bearing 6001, so that the whole transmission system can be assembled more conveniently, and the assembly can be performed in a direction from small to large in size.

Moment sensor 6300 is fixedly connected with middle shaft 6100 through a spline; the middle shaft 6100 is a hollow tube shaft, and two ends of the middle shaft 6100 are respectively connected with a crank.

As shown in fig. 27 to 29, the mid-motor according to the embodiment of the present utility model further includes the rotor core 2200, the first rotation shaft 2300, the rotor, the primary transmission gear 4100, the primary transmission gear 4200, or the middle shaft transmission mechanism 6000 provided in the above embodiment, or the transmission system provided in the above embodiment, and the first rotation shaft 2300 is mounted on the rotor core 2200.

The centrally-mounted motor provided by the embodiment reduces or eliminates the jumping problem caused by the fact that the rotating shaft is pressed into the rotor core due to the fact that gaps are staggered, so that the motor and the centrally-mounted motor rotate more stably, the pressing force is greatly reduced or even completely eliminated due to the design of the separation grooves, and meanwhile the problems that the stress area of the end face of the rotating shaft is reduced due to the grooves, and tooth surface deformation is caused by the fact that inductive magnetic steel connected through interference fit is used are overcome.

In the centrally-mounted motor provided in this embodiment, due to the design of the partition groove, when the tooth-shaped portion of the rotating shaft is pressed into the rotating shaft mounting hole of the rotor core, the non-meshing area bears the impact force, so that the deformation generated by the tooth surface is not conducted to the meshing area, and the tooth shape of the meshing area is ensured to be unchanged. Meanwhile, the rotating shaft provided by the utility model also solves the problems that the stress area of the end face of the rotating shaft is reduced due to the grooves, and the tooth surface is deformed due to the induction magnetic steel connected by interference fit.

In the centrally-mounted motor provided in this embodiment, the first rotating shaft 2300 of the rotor is connected with the rotor core 2200 by way of interference fit, and the problem of jumping after the rotating shaft is pressed into the rotor core due to the consistent position of the notch is reduced or eliminated by way of arranging the notch of the core sheet 2210 on the rotor core 2200.

In the center motor provided by the embodiment, the end part of the primary transmission gear shaft 4200 is provided with the support shaft 4230, the diameter of the support shaft 4230 is smaller, and the needle bearing with relatively smaller diameter is connected to the support shaft 4230, so that the transmission end of the primary transmission gear shaft 4200 is supported by the needle bearing, the problem of serious unilateral abrasion of the primary transmission gear shaft 4200 in the transmission process due to the suspension state is solved, the transmission stability of a transmission system is ensured, and the unilateral abrasion of the primary transmission gear shaft in the transmission process is reduced.

In the centrally-mounted motor provided by the embodiment, the first rotating shaft 2300 is adopted to directly drive the first-stage transmission gear 4100, so that the rotating speed of the first rotating shaft 2300 is high, the first-stage transmission gear 4100 made of integral metal materials has larger moment of inertia, and energy loss is caused; the first-stage transmission gear 4100 made of non-metal materials has the problems that the contact surface stress is large and the supporting strength can not meet the transmission requirement; therefore, the central insert 4120 made of metal material and the outer ring gear 4110 made of non-metal material are adopted in the present embodiment, and the width of the outer ring gear 4110 is made larger than that of the central insert 4120, so that on one hand, a larger contact area between the outer ring gear 4110 and the first rotation shaft 2300 is ensured, the contact stress of the outer ring gear 4110 is reduced, on the other hand, the rotational inertia of the central insert 4120 and the outer ring gear 4110 is lower, the energy loss in the transmission process is reduced, and on the other hand, the requirement of transmission torque can be met due to the smaller size of the central insert 4120 made of metal material.

The present embodiment also provides an electric bicycle, including the first rotation shaft 2300 provided in the above embodiment, or the detection system provided in the above embodiment, or the transmission system provided in the above embodiment, or the middle motor provided in the above embodiment, and the corresponding beneficial effects thereof are not repeated.

As shown in fig. 30-32, an embodiment of the present utility model further provides a center motor using a rotary transformer, including a motor assembly 2000, a main housing 1000, a transition housing 1200, a motor cover 1100, and a rotary transformer 3000, wherein:

the motor assembly 2000 includes a stator 2100, a rotor, and a first and second rotation shafts 2300A, the first and second rotation shafts 2300A including a rotor connection portion 2340, a power output end 2350, and a rotation mounting end 2360, the rotor connection portion 2340 being located between the power output end 2350 and the rotation mounting end 2360, a rotor core 2200 of the rotor being connected to the rotor connection portion 2340;

the main housing 1000 is provided with a stator mounting portion 1010 for accommodating the stator 2100, the stator mounting portion 1010 is separated from the inside of the main housing 1000 by a partition 1020, the opening of the stator mounting portion 1010 is outward, a rotary mounting end 2360 of the first second rotary shaft 2300A extends outward from the opening of the stator mounting portion 1010, and a power output end 2350 of the first second rotary shaft 2300A extends inward through the partition 1020 and is positioned in the main housing 1000;

The transition housing 1200 is abutted with an opening of the stator mounting portion 1010 of the main housing 1000 to form a motor mounting chamber 1001, the transition housing 1200 is provided with a shaft hole 1210 allowing the rotation shaft to pass through, and a rotation-varying mounting end 2360 is located outside the shaft hole 1210;

the motor cover 1100 is coupled to the transition housing 1200 outside the shaft hole 1210 to form a rotational mounting cavity 1002 outside the shaft hole 1210 and to accommodate the rotational mounting end 2360 therein;

resolver 3000 is located in a resolver mounting cavity, comprising resolver stator 3100 and resolver rotor 3200, with resolver rotor 3200 mounted at resolver mounting end 2360.

The centrally-mounted motor provided by the embodiment uses the rotary transformer 3000 to synchronously rotate under the drive of the rotor, so that the working state of the rotor can be detected in real time, and the centrally-mounted motor can control the motor component more accurately. In the centrally-mounted motor provided by the embodiment, the motor installation cavity 1001 and the rotary transformer installation cavity 1002 which are independent of the transmission cavity 1003 in the motor housing 1000 are formed by butting the main housing 1000, the transition housing 1200 and the motor cover 1100, so that the assembly of the motor assembly 2000, the first and second rotating shafts 2300A and the rotary transformer 3000 is facilitated, the motor installation cavity 1001 and the rotary transformer installation cavity 1002 are mutually isolated by the transition housing 1200, the rotary transformer 3000 and the motor assembly 2000 can be isolated, and electromagnetic interference between the rotary transformer 3000 and the motor assembly 2000 in the rotating process is prevented. In the middle motor in this embodiment, the main housing 1000 is abutted with the transition housing 1200, and then the transition housing 1200 is abutted with the motor cover 1100, and the rotary transformer mounting cavity 1002 is configured by the butt joint of the transition housing 1200 and the motor cover 1100, so that the rotary transformer 3100 can be conveniently fixed on the transition housing 1200 or the motor cover 1100.

In this embodiment, the walls of the main housing 1000 and the transition housing 1200 are respectively provided with mutually communicated lead channels, the lead channels are communicated with the inside of the main housing and the rotary mounting cavity, and wires are arranged in the lead channels to connect the rotary stator to the circuit board in the main housing. Through the design structure of the lead channel, the safety requirements of the middle motor can be ensured.

The embodiment of the utility model also provides a middle motor using the rotary transformer, which comprises a motor assembly 2000, a main machine shell 1000, a transition shell 1200, a motor cover 1100 and a rotary transformer 3000.

The transition housing 1200 is connected with the stator mounting portion 1010 of the main housing 1000 to form a motor mounting cavity 1001, the transition housing 1200 is provided with a shaft hole 1210 allowing the rotation shaft to pass through, and the rotational mounting end 2360 is located outside the shaft hole 1210;

the motor cover 1100 is abutted with the opening of the stator mounting portion 1010 of the main housing 1000 to form a rotation-varying mounting cavity 1002 outside the shaft hole 1210 and to accommodate the rotation-varying mounting end 2360 therein;

The centrally-mounted motor provided by the embodiment uses the rotary transformer 3000 to synchronously rotate under the drive of the rotor, so that the working state of the rotor can be detected in real time, and the centrally-mounted motor can control the motor component more accurately. In the centrally-mounted motor provided by the embodiment, the motor installation cavity 1001 and the rotary transformer installation cavity 1002 which are independent of the transmission cavity 1003 in the motor housing 1000 are formed by butting the main housing 1000, the transition housing 1200 and the motor cover 1100, so that the assembly of the motor assembly 2000, the first and second rotating shafts 2300A and the rotary transformer 3000 is facilitated, the motor installation cavity 1001 and the rotary transformer installation cavity 1002 are mutually isolated by the transition housing 1200, the rotary transformer 3000 and the motor assembly 2000 can be isolated, and electromagnetic interference between the rotary transformer 3000 and the motor assembly 2000 in the rotating process is prevented. In the middle motor in this embodiment, a manner of butting the main housing 1000 with the motor cover 1100 is adopted, and a manner of arranging the transition housing 1200 inside separates a chamber formed by the main housing 1000 and the motor cover 1100 into a rotary mounting chamber 1002 and a motor mounting chamber 1001 which are independent of each other, so that the rotary stator 3100 can be conveniently fixed on the transition housing 1200 or the motor cover 1100.

In this embodiment, a lead channel is provided on the wall of the main housing 1000, the lead channel communicates with the spin-on mounting cavity 1002 and the transmission cavity 1003 of the 1000 part inside the main housing, and wires are arranged in the lead channel to connect the spin-on stator to the circuit board 7100 inside the main housing. Through the design structure of the lead channel, the safety requirements of the middle motor can be ensured.

The above examples provide two embodiments of a center motor using a resolver, and both embodiments of the resolver are mounted on the non-power output end of the first and second shafts 2300A, since the wires of the resolver need to be connected to the wiring board 7100 inside the center motor to transmit the induction signal to the wiring board 7100, and the wiring board 7100 is typically the transmission chamber 1003 provided in the main housing 1000, but the transmission chamber 1003 is not connected to or adjacent to the resolver mounting chamber 1002, so that the wires need to be connected to the wiring board through the wire path. Further optimization of the above two embodiments is described below:

in this embodiment, the stator mounting portion 1010 and the partition 1020 may be integrally formed on the main housing 1000, or may be connected to the main housing 1000 in a split structure.

In this embodiment, a first fixing structure is provided on the transition housing 1200 outside the shaft hole 1210 to fix the rotation stator 3100. Through the mode that the transition casing 1200 will revolve the stator 3100 and fix, can make the resolver be close to motor installation cavity 1001 more to make the length of first second pivot 2300A reduce, overall structure is compacter, also makes the installation and the fixation of revolve the stator 3100 more convenient simultaneously.

In this embodiment, the first fixing structure includes an annular rib 1220 disposed on the transition housing 1200 and coaxially disposed with the shaft hole 1210, and a fixing block 1230 is disposed on the outer side of the annular rib 1220, where the fixing block 1230 is connected to the transition housing 1200 and abuts against the outer portion of the rotary stator 3100. The annular ribs 1220 provide a reference for fixing the rotary stator 3100, and since the transition housing 1200 is directly connected with the main housing 1000, the coaxiality of the annular ribs 1220 and the motor assembly 2000 is better, so that the rotary stator 3100 and the rotary stator 3200 mounted on the first and second rotating shafts 2300A are better assembled. The annular bead 1220 may further increase the structural strength of the transition housing 1200, thereby increasing the resistance of the transition housing 1200 to deformation.

In this embodiment, the fixing block 1230 has an arc structure, and the radian of the abutting part of the rotary stator 3100 is the same, and the rotary stator 3100 is abutted by the fixing block 1230 with an arc structure, so that the assembly accuracy of the rotary stator 3100 can be ensured to be better.

In this embodiment, an annular groove 3120 is provided at the abutting portion of the rotation stator 3100, and the fixing block 1230 has an arc adapted to the annular groove 3120. The fixing block 1230 can be clamped in the annular groove 3120 on the rotary stator 3100, so that the fixing block 1230 can perform fixing and centering functions on the rotary stator 3100 after being connected with the rotary stator 3100.

In this embodiment, a bearing installation chamber 1240 is provided in the transition housing 1200 inside the shaft hole 1210, and a bearing is installed in the bearing installation chamber 1240 and is sleeved on the first and second rotating shafts 2300A. The bearing installation chamber 1240 also adopts an annular structure, and similar to the annular rib 1220, the structural strength of the transition housing 1200 can be further improved. Meanwhile, the bearing is installed in the bearing installation chamber 1240, which can provide support for the first and second rotation shafts 2300A, thereby making the structural layout more reasonable.

In this embodiment, a second fixing structure may be provided on the inner side of the motor cover 1100 to fix the rotary stator. The second fixing structure has substantially the same function as the first fixing structure, and fixes the rotary stator 3100, except that the second fixing structure is disposed at the inner side of the motor cover 1100, and the first fixing structure is disposed on the transition housing 1200. The specific design of the second fastening structure may be referred to as the first fastening structure.

In this embodiment, the transition housing 1200 is made of a magnetically insulating material; thus, better isolation of motor assembly 2000 from resolver 3000 is achieved, reducing or eliminating electromagnetic interference therebetween.

In this embodiment, the power take off 2350 processes gears; reference may be made specifically to the structural design of the first rotation shaft 2300 in the above embodiment, and details thereof will not be repeated here. When the power output end 2350 directly processes the gear, the transmission effect of the middle motor is better, the structure is more compact, the cost can be reduced, and the transmission efficiency is improved.

In this embodiment, an end surface of the rotary mounting end 2360 is connected to the third fixing structure 2361 to fix the rotary rotor 3200. The third fixing structure 2361 is a nut, and the size of the nut is larger than the end surface diameter of the rotational mounting end 2360.

In this embodiment, two or three annular grooves 1011 are provided in the circumferential direction of the inner wall of the stator mounting portion 1010, and the annular grooves 1011 are filled with a colloid, so that the colloid is connected with the stator core after the stator core is mounted in the mounting cavity. The stator core is connected in the stator mounting portion 1010 of the main housing 1000 by way of injecting glue into the annular groove 1011, so that the stator core can be better fixed, and the stator core can be kept fixed in the running process of the motor assembly 2000. In this embodiment, a plurality of segments of arc grooves may be used instead of the annular groove 1011, or the arc grooves and the annular groove 1011 may be combined to fix the stator core. Those skilled in the art will appreciate that the manner of the multi-segment arcuate slot may better overcome the circumferential movement of the stator core.

In this embodiment, the connection parts of the annular groove 1011 and the arc-shaped groove far from one side of the opening and the inner wall of the stator mounting part 1010 are chamfer angles, round angles or inclined planes; thereby further facilitating the assembly of the stator core into the stator mounting section 1010.

In this embodiment, the surfaces in the annular groove 1011 and the arc-shaped groove are set as friction surfaces, so that after glue injection, the contact area between the glue and the groove is larger, and the fixing effect is better.

In this embodiment, the outer part of the main housing 1000 is further provided with a heat dissipation rib 1030, and the heat dissipation rib 1030 is perpendicular to the axial direction of the first and second rotating shafts 2300A and corresponds to the position of the stator. In the implementation process, the heat dissipation ribs may be disposed at positions corresponding to other heat generating structures of the main housing 1000, and the effect thereof is substantially the same as that of the heat dissipation ribs 1030 in the present embodiment.

In this embodiment, the top edge of the heat sink rib 1030 is highly aligned with the outer surface of the main chassis 1000 where the heat sink rib 1030 is not provided; thereby ensuring that the heat dissipation ribs 1030 and the outer surface of the main housing 1000 have the same external dimensions, and avoiding the heat dissipation ribs 1030 from being damaged when the heat dissipation ribs 1030 protrude out of the surface of the main housing 1000 and collide with the outside.

In this embodiment, the arrangement direction of the heat dissipating ribs 1030 is the same as the forward direction of the central motor along with the forward direction of the bicycle, so that the air flow can pass through between the heat dissipating ribs while the bicycle is forward, and the heat dissipating effect is improved.

The middle motor provided in this embodiment and installed with a rotary transformer at the non-power output end of the rotating shaft may further use a stator core, the rotating shaft, a primary transmission gear shaft, a middle motor transmission mechanism, etc., and specific reference may be made to the description of the above embodiments, which is not repeated herein.

As shown in fig. 33-36, the present embodiment further provides a central motor using a rotary transformer, where the rotary transformer in the present embodiment is located at a power output end of a motor assembly 2000, and the central motor provided in the present embodiment includes the motor assembly 2000, a main housing 1000, and a rotary transformer 3000, where:

the motor assembly 2000 includes a stator 2100, a rotor, and a first third rotation shaft 2300B, the first third rotation shaft 2300B including a rotor connection end 2370, a power output portion 2380, and a rotation mounting end 2360, wherein the power output portion 2380 is located between the rotation mounting end 2360 and the rotor connection end 2370, and the rotor is mounted on the rotor connection end 2370;

The inside of the main machine shell 1000 is divided into a motor installation cavity 1001 and a transmission cavity 1003 by a partition board, a first third rotating shaft 2300B passes through a through hole on the partition board, and a stator 2100, a rotor and a rotor connecting end 2370 of the first third rotating shaft 2300B are positioned in the motor installation cavity 1001; the power output portion 2380 and the rotary mounting end 2360 of the first third rotation shaft 2300B are positioned in the transmission cavity 1003;

the rotary transformer 3000 is located in the transmission cavity 1003, and includes a rotary stator 3100 and a rotary rotor 3200, wherein the rotary rotor 3200 is mounted on a rotary mounting end 2360 of the first third rotary shaft 2300B, and the rotary stator 3100 is fixedly connected in the main housing 1000 through a first fixing structure.

In the centrally-mounted motor provided in this embodiment, a rotary mounting end 2360 is disposed on the outer side of a power output portion 2380 of a first third rotating shaft 2300B for mounting a rotary rotor 3200 of a rotary transformer 3000, so that the problem that in the prior art, inductive magnetic steel is mounted on the power output end of the first rotating shaft 2300 (as shown in fig. 29), the first rotating shaft 2300 causes deformation of the tooth surface when being pressed into a rotor core 2200 is avoided, and the motor is directly connected to the first third rotating shaft 2300B through the rotary transformer 3000, so that the motor can rotate synchronously with the first third rotating shaft 2300B, and the induction signal detected by the inductive magnetic steel is more accurate than that detected by the inductive magnetic steel.

In the middle motor provided in this embodiment, since the rotary transformer 3000 is disposed in the transmission cavity 1003 of the main housing 1000, and the circuit board 7100 is also disposed in the transmission cavity 1003, the rotary transformer 3000 may be directly connected to the circuit board 7100, and the above embodiment is not required to connect the rotary transformer to the non-power output end of the rotating shaft, and a complex structural design for designing the routing channel for the routing wire of the rotary transformer stator is required.

The centrally-mounted motor provided in this embodiment further includes a circuit board 7100, which is disposed in the transmission cavity 1003, and the rotary stator 3100 is connected to the circuit board 7100 through a wire.

The centrally-mounted motor provided in this embodiment further includes a motor cover 1100 connected to the motor mounting cavity 1001 of the main housing 1000;

a first bearing installation chamber 1110 is provided in the motor cover 1100, and the first third rotation shaft 2300B is coupled to the first bearing installation chamber 1110 through a first ball bearing 1111. A second bearing mounting chamber 1022 is provided on the partition 1020 surrounding the inside of the through hole, and the first and third rotation shafts 2300B are connected in the second bearing mounting chamber 1022 through a second ball bearing 1023. The two bearing chambers and the bearing therein can provide a supporting function to the first third rotation shaft 2300B.

The centrally-mounted motor provided by the embodiment further comprises a main machine cover 1300 which is connected with the transmission cavity of the main machine shell 1000;

a first fixing structure is provided at a position corresponding to the spin-mount end 2360 inside the main body cover 1300 to fix the spin-set stator 3100.

In this embodiment, the first fixing structure includes an annular rib 1220 disposed inside the main cover 1300 and coaxially disposed with the shaft hole 1210, and a fixing block 1230 is disposed outside the annular rib 1220, where the fixing block 1230 is connected inside the main cover 1300 and abuts against the outside of the rotary stator 3100. The annular ribs 1220 provide a reference for fixing the rotary stator 3100, and since the main body cover 1300 is directly connected with the main body case 1000, the coaxiality of the annular ribs 1220 and the motor assembly 2000 is better, so that the rotary stator 3100 and the rotary stator 3200 mounted on the first third rotary shaft 2300B are better assembled. The annular ribs 1220 may further improve the structural strength of the main cover 1300, thereby improving the deformation resistance of the main cover 1300.

The middle motor provided in this embodiment and installed with a rotary transformer at the power output end of the rotating shaft may further use a stator core, the rotating shaft, a primary transmission gear shaft, a middle motor transmission mechanism, etc., and specific reference may be made to the related description of the above embodiments, which is not repeated herein.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The foregoing examples illustrate only a few embodiments of the utility model, which are described in detail and are not to be construed as limiting the scope of the utility model. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the utility model, which are all within the scope of the utility model. Accordingly, the scope of protection of the present utility model is to be determined by the appended claims.

Claims

1. A bottom bracket drive mechanism, comprising:

a middle shaft (6100) for mounting a crank and a pedal to bear the riding pedal force;

a moment sensor (6300) capable of detecting a pedaling force provided to the bicycle by a rider and fixedly installed on the bottom bracket;

a dental tray positioning sleeve (6200), one end of which is connected with the moment sensor through a first isolator (6500), and the other end of which is fixedly connected with the dental tray;

a middle shaft gear (6400) connected to the dental tray positioning sleeve through a second isolator (6600);

the dental tray connecting structure (6700) is fixedly connected to the dental tray positioning sleeve (6200) and is positioned at the outer side of the middle shaft gear (6400) for being connected with a dental tray;

wherein, the axis drive mechanism includes helping hand operating mode and non-helping hand operating mode: when the middle shaft transmission mechanism is in a power-assisted working mode, the first isolator (6500) and the second isolator (6600) are in a transmission state; when the bottom bracket drive mechanism is in a non-power-assisted working mode, the first isolator (6500) and the second isolator (6600) are in a disengaged state.

2. The bottom bracket transmission mechanism according to claim 1, wherein,

The bottom bracket gear (6400) includes:

a gear part (6410);

a support portion (6420) located correspondingly inside the gear portion (6410) in the radial direction, for connection with the dental disc positioning sleeve (6200) through a third ball bearing (6003);

and a transmission part (6430) which is positioned on one side of the supporting part (6420) in the axial direction and is used for being connected with the dental tray positioning sleeve (6200) through the second isolator (6600).

3. The bottom bracket transmission mechanism according to claim 2, wherein,

the gear portion (6410), the support portion (6420), the transmission portion (6430) form an L-shaped layout, and the transmission portion (6430) is located outside the support portion (6420) in the axial direction.

4. The bottom bracket transmission mechanism according to claim 3, wherein,

the dental tray positioning sleeve (6200) is provided with an annular step structure (6210), wherein the first isolator (6500) is arranged in the annular step structure (6210), the second isolator (6600) is close to the annular step structure (6210), and the outer diameter of the transmission part (6430) does not exceed the outer diameter of the annular step structure (6210).

5. The bottom bracket transmission mechanism according to claim 3, wherein,

The inside of the dental tray positioning sleeve (6200) is connected with the middle shaft through two needle bearings, and the two needle bearings are correspondingly positioned at two sides of the supporting part.

6. The bottom bracket transmission mechanism according to claim 5, wherein,

the two needle bearings are a second needle bearing (6001) and a third needle bearing (6002) respectively, wherein the second needle bearing (6001) is positioned at the outer side of the third needle bearing (6002), and the third needle bearing (6002) is connected to the torque sensor (6300).

7. The bottom bracket transmission mechanism according to claim 6, wherein,

the third needle bearing (6002) has an inner diameter greater than the inner diameter of the second needle bearing (6001).

8. The bottom bracket transmission mechanism according to claim 1, wherein,

the moment sensor (6300) is fixedly connected with the middle shaft (6100) through a spline; the middle shaft (6100) is a hollow pipe shaft, and two ends of the middle shaft (6100) are respectively connected with a crank.

9. A transmission system, characterized by comprising a motor assembly (2000), a reduction mechanism and a bottom bracket drive mechanism (6000) according to any one of claims 1-4, wherein a first rotation shaft (2300) of the motor assembly (2000) drives the bottom bracket gear (6400) to drive through the reduction mechanism.

10. The transmission system according to claim 9, wherein the transmission system is configured to transmit the torque of the transmission system,

the speed reducing mechanism is a primary speed reducer or a secondary speed reducer.

11. The transmission system according to claim 9, wherein the transmission system is configured to transmit the torque of the transmission system,

the speed reducing mechanism is a three-stage speed reducer, and the speed reducing mechanism comprises:

a primary drive wheel set (4000) comprising a primary drive gear (4100) and a primary drive gear shaft (4200), the primary drive gear (4100) being in mesh with the first rotation shaft (2300), the primary drive gear shaft (4200) being coaxially connected with the primary drive gear (4100);

a secondary transmission gear set (5000) meshed with the primary transmission gear shaft (4200);

wherein, the middle shaft gear (6400) is meshed with the two-stage transmission wheel set (5000) for transmission.

12. The transmission system of claim 11, wherein the transmission system is configured to transmit power from the transmission system to the transmission system,

the primary transmission gear shaft (4200) comprises an input end (4210), an output gear portion (4220) and a support shaft (4230), wherein the input end (4210) is connected with a central insert (4120), the output gear portion (4220) is located between the input end (4210) and the support shaft (4230), the diameter of the support shaft (4230) is smaller than that of the output gear portion (4220) and the input end (4210), and the support shaft (4230) is connected with a first needle bearing (4240).

13. The drive system of claim 12, wherein an outer diameter of the first needle bearing (4240) is less than a top circle diameter of the output tooth (4220).

14. The transmission system of claim 12, wherein the secondary drive pulley set (5000) comprises a secondary drive gearwheel (5100) and a secondary drive pinion (5200) coaxially connected, the secondary drive gearwheel (5100) being in mesh with the primary drive gear shaft (4200), the secondary drive pinion (5200) being in mesh with the bottom bracket gear (6400); wherein the secondary drive pinion (5200) is located on a side remote from the primary drive gear shaft (4200) such that the secondary drive pinion (5200) corresponds radially to the position of the first needle bearing (4240).

15. A mid-motor comprising a housing, a bottom bracket drive as claimed in any one of claims 1 to 8 or a drive system as claimed in any one of claims 9 to 14, said bottom bracket drive or said drive system being mounted within said housing.

16. The center motor of claim 15, further comprising

A motor assembly (2000) including a stator (2100), a rotor, and a second rotating shaft (2300A), the second rotating shaft (2300A) including a rotor connection portion (2340), a power output end (2350), and a rotation mounting end (2360), the rotor connection portion (2340) being located between the power output end (2350) and the rotation mounting end (2360), a rotor core (2200) of the rotor being connected to the rotor connection portion (2340);

The motor comprises a main machine shell (1000), wherein a stator mounting part (1010) for accommodating the stator (2100) is arranged in the main machine shell (1000), the stator mounting part (1010) is separated from the inside of the main machine shell (1000) through a partition plate (1020), an opening of the stator mounting part (1010) faces outwards, a rotary mounting end (2360) of a second rotating shaft (2300A) extends outwards from the opening of the stator mounting part (1010), and a power output end (2350) of the second rotating shaft (2300A) penetrates through the partition plate (1020) to extend inwards and is positioned in the main machine shell (1000);

a transition housing (1200) interfacing with an opening of a stator mounting portion (1010) of the main housing (1000) to form a motor mounting chamber (1001), the transition housing (1200) being provided with a shaft hole (1210) allowing the rotation shaft to pass therethrough, and the rotation-varying mounting end (2360) being located outside the shaft hole (1210);

a motor cover (1100) connected to the transition housing (1200) outside the shaft hole (1210) to form a rotational mounting cavity (1002) outside the shaft hole (1210) and to accommodate the rotational mounting end (2360) therein;

and the rotary transformer (3000) is positioned in the rotary mounting cavity and comprises a rotary stator (3100) and a rotary rotor (3200), wherein the rotary rotor (3200) is mounted at the rotary mounting end (2360).

17. The center motor of claim 15, further comprising

a transition housing (1200) connected with a stator mounting part (1010) of the main housing (1000) to form a motor mounting cavity (1001), the transition housing (1200) being provided with a shaft hole (1210) allowing the rotation shaft to pass through, and the rotation-varying mounting end (2360) being located outside the shaft hole (1210);

A motor cover (1100) which is butted with an opening of a stator mounting part (1010) of the main machine shell (1000) to form a rotary mounting cavity (1002) outside the shaft hole (1210) and accommodate the rotary mounting end (2360) therein;

18. The center motor of claim 15, further comprising:

a motor assembly (2000) comprising a stator (2100), a rotor and a third shaft (2300B), the third shaft (2300B) comprising a rotor connection end (2370), a power take-off (2380) and a torque-on mounting end (2360), wherein the power take-off (2380) is located between the torque-on mounting end (2360) and the rotor connection end (2370), the rotor being mounted on the rotor connection end (2370);

the motor comprises a main machine shell (1000), wherein the inside of the main machine shell (1000) is divided into a motor mounting cavity (1001) and a transmission cavity (1003) through a partition board, a third rotating shaft (2300B) passes through a through hole on the partition board, and a stator (2100), a rotor and a rotor connecting end (2370) of the third rotating shaft (2300B) are positioned in the motor mounting cavity (1001); the power output part (2380) and the rotary mounting end (2360) of the third rotating shaft (2300B) are positioned in the transmission cavity (1003);

The rotary transformer (3000) is located in the transmission cavity (1003) and comprises a rotary stator (3100) and a rotary rotor (3200), wherein the rotary rotor (3200) is installed at a rotary installation end (2360) of the third rotating shaft (2300B), and the rotary stator (3100) is fixedly connected in the main casing (1000) through a first fixing structure.