CN219857509U - Stepless speed change central motor - Google Patents

Abstract

The utility model relates to a stepless speed change middle motor, which comprises a shell, a power-assisted motor, a generator and a middle shaft, wherein a left half shaft is connected with a torque sensor, the torque sensor is connected with a first planet carrier, a gear ring support frame is supported on the first planet carrier, a first gear ring and a third gear ring are fixedly connected on the gear ring support frame, the first gear ring is meshed with a first planet wheel, and the first planet wheel is meshed with a first sun wheel to form a first speed change structure; the third gear ring is meshed with a right side gear of the duplex planet gear, a left side gear of the duplex planet gear is meshed with a second gear ring fixed on the shell, the left side gear is meshed with a third sun gear, and the third sun gear is fixedly connected with a generator rotor to form a second speed change structure; the input gear of the first planet carrier is meshed with the transition gear and is meshed with the output shaft gear of the power-assisted motor. The beneficial effects are that: the manual power and the power-assisted motor power are intersected with each other to be output after being changed in speed by the first planet carrier of the planetary gear speed change mechanism, and a rider can ride with the most comfortable force and pedal frequency.

Description

Stepless speed change central motor

Technical Field

The utility model belongs to the technical field of centrally-mounted motors of power-assisted bicycles, and particularly relates to a stepless speed change centrally-mounted motor.

Background

In most of centrally-mounted transmission of electric bicycles in the current market, a gear transmission mechanism is used for connecting a motor and a tooth disc, and the speed change function of a centrally-mounted transmission system is realized by increasing the number of gears. The speed change system has high requirements on the strength and the service life of gears, has high production cost, and can possibly generate the situation of discontinuous speed change during speed change. The prior art provides a bicycle provided with a built-in stepless speed change central motor, which can automatically adjust the output speed according to riding resistance to realize stepless speed change. For example, the applicant discloses in the patent application number 202211527942.6 a self-adaptive stepless speed change central motor, which comprises a shell, a booster motor, a main motor, a generator and a central shaft, and is characterized in that: the rotor of the power-assisted motor is connected with the output shaft of the power-assisted motor through a one-way clutch of the power-assisted motor, the rotor of the main motor is coaxially connected with the output shaft of the power-assisted motor through the one-way clutch of the main motor, the output shaft of the power-assisted motor is supported on the shell through a bearing, and the gear at the output end of the output shaft of the power-assisted motor is meshed with an output speed reducing mechanism; the power-assisted motor is characterized in that a rotor of a generator is connected to the center shaft, the rotor of the generator is coaxially connected with the planetary speed increasing mechanism, and the generator, the power-assisted motor and the main motor form a stepless speed change motor combined structure. Chinese patent with patent grant publication number CN107685828B discloses a stepless speed change transmission device for electric bicycle, comprising a first motor, a second motor, a central shaft and a planetary gear mechanism coaxially arranged with the central shaft; the planetary gear mechanism comprises a sun gear, an inner gear ring, an outer gear ring, a planetary carrier and a planetary gear, wherein the sun gear is sleeved on a central shaft through a clutch, the inner gear ring and the outer gear ring are provided with gear ring inner teeth and gear ring outer teeth, the planetary gear is circumferentially uniformly distributed on the planetary carrier and is respectively meshed with the sun gear and the gear ring inner teeth, the first motor is meshed with the gear ring outer teeth through gears, one axial side of the planetary carrier is meshed with the second motor through gears, and the other axial side of the planetary carrier is provided with an output toothed disc assembly fixedly connected with the second motor. The utility model realizes stepless speed change output by adding the motor, and ensures the smoothness and continuity of speed change. Although the two middle motors can realize stepless speed change in a relatively large output rotating speed range, only human power is output through the speed change mechanism in the structure, and the power of the power-assisted motor is not output through the speed change mechanism, so that the power-assisted motor works in a relatively large speed range, and the efficiency is low. Meanwhile, the second patent technology has the more outstanding defect that the force acting point is not placed on the shell, (the first motor is used as an input end, the middle shaft and the second motor do not output power, the input power is transmitted to the planetary gear through the first output shaft gear and the inner gear ring, the outer gear ring, and the sun gear generates clutch with the middle shaft through the needle roller clutch, the planetary gear mechanism rotates around the middle shaft under the drive of the planetary gear, the output dental tray component rotates along with the planetary gear, and the electric bicycle is driven to advance.) the structure can generate the possibility that the pedals reversely and rapidly rotate when the human feet do not step on the pedals, and is very dangerous.

Disclosure of Invention

The utility model aims to overcome the defects of the technology and provide a stepless speed change middle motor, which ensures that the manual power and the power of a power-assisted motor are output through speed change by the cooperative function of the combination of two groups of planetary gear speed change structures, thereby improving the working efficiency of the power-assisted motor and the comfort of a rider.

The utility model adopts the following technical scheme to realize the aim: the utility model provides a put motor in infinitely variable speed, includes casing, helping hand motor, generator, axis and planet wheel variable speed structure, characterized by: the center shaft penetrates through the center of the generator and the planetary gear speed change structure, the center shaft comprises a left half shaft and a right half shaft, the left half shaft is connected with a torque sensor through a first one-way clutch, the torque sensor is connected with a first planet carrier, the left half shaft is supported on a shell through a left half shaft supporting bearing, the right half shaft is connected with the first planet carrier in a sliding manner, a gear ring supporting frame is supported on the first planet carrier through a first gear ring supporting frame supporting bearing, a first gear ring and a third gear ring which is integrated with the first gear ring are fixedly connected on the gear ring supporting frame, the first gear ring is meshed with the first planet, the first planet carrier is supported on a first planet supporting shaft through a first planet supporting bearing, and the first planet is meshed with the first sun gear to form the first planetary gear speed change structure; the third gear ring is meshed with a right gear of the duplex planet gear, a left gear of the duplex planet gear is meshed with a second gear ring fixed on the shell, the left gear is meshed with a third sun gear, the duplex planet gear is supported on a duplex planet gear supporting shaft through a duplex planet gear supporting bearing, the duplex planet gear supporting shaft is supported on a second planet carrier, the second planet carrier is supported on a first planet carrier through a second planet carrier supporting bearing, and the third sun gear is fixedly connected with a generator rotor to form a second planet gear speed change structure; a second one-way clutch is arranged between the gear ring support frame and the first planet carrier, the outer circle of the tooth disc output shaft is supported on the shell through a tooth disc output shaft supporting bearing, the inner circle of the tooth disc output shaft is supported on the right half shaft of the middle shaft through a sun gear output shaft supporting bearing, an input gear of the outer circle of the first planet carrier is meshed with a transition gear, and the transition gear is meshed with an output shaft gear of the booster motor.

Further, a middle shaft end ratchet is arranged on the left half shaft of the middle shaft, and a moment sensor end ratchet is arranged on the inner ring of the moment sensor to form a first one-way clutch structure.

Further, the gear ring support frame is provided with a gear ring support frame end ratchet, and the first planet carrier is provided with an output mechanism planet carrier end ratchet to form a second one-way clutch structure.

Further, the left half shaft and the right half shaft are connected in an inserting mode through a spline.

Further, rectangular teeth are axially arranged on the end face of the moment sensor and are in key joint with the rectangular teeth on the end face of the first planet carrier.

The beneficial effects are that: compared with the prior art, the utility model has compact structure and smaller radial size, and the manual power and the power of the power-assisted motor are converged on the first planet carrier of the planetary gear speed change mechanism and then output after speed change, so that the acting force of the speed change motor is prevented from influencing the reverse rotation of the middle shaft, a rider can ride with the most comfortable force and pedal frequency, the power-assisted motor also works in a high-efficiency interval, the working efficiency of the power-assisted motor is improved, and the riding comfort is improved.

Drawings

FIG. 1 is a cross-sectional view of a central motor of the present utility model;

FIG. 2 is a schematic diagram of the continuously variable transmission of the present utility model in combination with an electric motor;

FIG. 3 is an exploded right perspective view of the center motor of the present utility model;

FIG. 4 is an enlarged view of a portion of FIG. 3;

FIG. 5 is an exploded left perspective view of the center motor of the present utility model;

FIG. 6 is an enlarged view of a portion of FIG. 5;

FIG. 7 is a schematic diagram of a mid-motor torque sensor connection in accordance with the present utility model;

fig. 8 is a schematic block diagram of the present utility model.

In the figure: 1. a right half shaft, 1-1, a left half shaft, 1-2, a middle shaft end ratchet, 1-3, a left half shaft spline, 1-4, a right half shaft spline, 1-5, a sun gear output shaft supporting bearing, 1-6, a left half shaft supporting bearing, 2, a torque sensor, 2-1, a torque sensor end ratchet, 2-2, a torque sensor end rectangular tooth, 3, a first planet carrier, 3-1, a first planet carrier end ratchet, 3-2, a first planet carrier end motor power input gear, 3-3, a first planet carrier left rectangular tooth, 4, a first planet carrier supporting shaft, 4-1, a first planet carrier supporting bearing, 5, a first planet gear, 6, a first gear ring, 7, a first sun gear, 7-1, a dental disc output shaft, 7-2, a dental disc output shaft supporting bearing, 8, a dental disc, 9, a first gear ring supporting frame, 9-1, a first gear ring support frame end ratchet, 9-2, a first gear ring support frame support bearing, 10, a third gear ring, 11, a double planetary gear right side gear, 11-1, a double planetary gear left side gear, 11-2, a double planetary gear support bearing, 14, a second gear ring, 12, a double planetary gear support shaft, 13, a second planetary carrier, 13-1, a second planetary carrier support bearing, 15, a second sun gear, 16, a generator rotor, 16-1, a generator rotor support bearing, 17, a generator stator, 18, a left side shell, 19, a right side shell, 20, a motor stator, 21, a motor rotor, 22, a motor one-way clutch, 23, a motor output shaft, 23-1, a motor output shaft gear, 23-2, a motor output shaft left side support bearing, 23-3, a right side supporting bearing of a motor output shaft, 24, a motor end cover, 25, a transition gear, 25-1, a transition wheel supporting bearing, 26, a controller, 26-1, a riding state signal, 26-2, a charging load control signal, 27, a charging load control unit, 28 and a battery.

Detailed Description

In order that the above-recited objects, features and advantages of the present utility model will be more clearly understood, a more particular description of the utility model will be rendered by reference to the appended drawings and appended detailed description. The embodiments of the present utility model and the features in the embodiments may be combined with each other without collision. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present utility model, and the described embodiments are merely some, rather than all, embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the present utility model without making any inventive effort, are intended to fall within the scope of the present utility model. 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.

In various embodiments of the utility model, for convenience in description and not limitation, the term "coupled" as used in the specification and claims is not limited to a physical or mechanical connection, but may include an electrical connection, whether direct or indirect. "upper", "lower", "left", "right", etc. are used merely to indicate a relative positional relationship, and when the absolute position of the object to be described is changed, the relative positional relationship is changed accordingly.

Referring to the drawings in detail, the embodiment provides a stepless speed change central motor, which comprises a shell, a booster motor, a generator, a central shaft and a planetary gear speed change structure, wherein the central shaft penetrates through the center of the generator and the planetary gear speed change structure, the central shaft comprises a left half shaft and a right half shaft, the left half shaft 1-1 is connected with a torque sensor 2 through a first one-way clutch, the torque sensor 2 is connected with a first planet carrier, the left half shaft is supported on the shell through a left half shaft support bearing 1-6, the right half shaft is in sliding connection with a first planet carrier 3, the first planet carrier 3 is supported with a gear support frame 9 through a first gear support frame support bearing 9-2, the first gear support frame 9 is fixedly connected with a first gear 6 and a third gear 10 which is in common with the first gear 6, the first gear is meshed with a first planet 5, the first planet is supported on the first planet support shaft 4-1 through a first planet support bearing 4-1, the first planet carrier 3 is supported on the first planet 5 and the first sun 7, and the first speed change structure is formed; the third gear ring 10 is meshed with a right gear 11 of the double planet wheel, a left gear 11-1 of the double planet wheel is meshed with a second gear ring 14 fixed on the shell, the left gear is meshed with a third sun gear 15, the double planet wheel is supported on a double planet wheel supporting shaft 12 through a double planet wheel supporting bearing 11-2, the double planet wheel supporting shaft is supported on a second planet carrier 13, the second planet carrier 13 is supported on a first planet carrier 3 through a second planet carrier supporting bearing 13-1, and the third sun gear 15 is fixedly connected with a generator rotor 16 to form a second planet wheel speed change structure; a second one-way clutch is arranged between the gear ring support frame 9 and the first planet carrier 3, the shell is provided with an outer circle of the gear disc output shaft 7-1 through the gear disc output shaft support bearing 7-2, the inner circle of the gear disc output shaft 7-1 is supported on the right half shaft 1 of the middle shaft through the sun gear output shaft support bearing 1-5, an input gear 3-2 of the outer circle of the first planet carrier 3 is meshed with a transition gear 25, and the transition gear is meshed with an output shaft gear 23-1 of the booster motor.

In the preferred scheme of the embodiment, a middle shaft end ratchet 1-2 is arranged on a middle shaft left half shaft 1-1, a moment sensor end ratchet 2-1 is arranged on the inner ring of a moment sensor 2, and a first one-way clutch structure is formed.

In the preferred scheme of the embodiment, the gear ring support frame 9 is provided with a gear ring support frame end ratchet 9-1, and the first planet carrier 3 is provided with an output mechanism planet carrier end ratchet 3-1 to form a second one-way clutch structure.

In the preferred scheme of the embodiment, the left half shaft and the right half shaft are connected in an inserting mode through a spline.

In the preferred embodiment, rectangular teeth are axially arranged on the end face of the torque sensor 2 and are in key joint with the rectangular teeth on the end face of the first planet carrier.

Principle of infinitely variable speed operation

As shown in fig. 1, two paths of power, i.e., the manpower power and the power of the booster motor, are collected in the first planet carrier input, output from the first sun gear, and the rotation speed of the first sun gear is changed when the rotation speed of the first gear ring is changed under the condition that the rotation speed of the planet carrier is unchanged according to the basic characteristics of the NGW planetary gear train.

When power is input to the first planet carrier, the first planet gears and the first planet carrier have a tendency to rotate in the rotation direction of the first planet carrier, and the specific rotation speeds of the first sun gear and the first gear ring depend on the resistance of the first gear ring. The gear ring has high resistance and low rotation speed, and has low resistance and high rotation speed. The first ring gear resistance is achieved by controlling the generator rotor resistance by controlling the charging load of the generator rotor. Under the condition that the power is input by the planet carrier, the speed of the generator rotor is low when the resistance of the generator rotor is high, and is high when the resistance is low. The rotating speed of the generator rotor is controlled by controlling the magnitude of the charging load so as to control the rotating speeds of the third gear ring and the first gear ring, and the rotating speed of the first sun gear is changed under the condition that the rotating speed of the first planet carrier is unchanged, namely the variable speed output.

The utility model relates to a riding road condition, which comprises three conditions of ascending, leveling and descending, and a rider can tread at the most comfortable tread frequency all the time (the tread frequency is the more comfortable frequency about 60 revolutions per minute in general) for the condition of the riding road condition.

The second ring gear 14 is fixed to the left side case 18, and the second ring gear and the third ring gear are simultaneously engaged by the double gear, so that the generator rotor can lock the third ring gear with a small force, and the shifting process can be stably controlled under the control of the charge load control unit.

The relation between the pedal frequency of a rider and the speed of the device of the utility model under different riding environments is further described:

the three conditions of high speed, low speed and medium speed are divided

1) When the vehicle is required to run in a high-speed gear, the charging load is increased to lock the third gear ring, namely the third gear ring is static, power is input from the first planet carrier and output from the first sun gear, and the rotating speed of the first planet carrier is n _{First planet carrier} The first sun gear increases speed to n _{First sun gear} Then, the step-up ratio i of the first planet carrier to the first sun gear _{First sun gear} = n _{First sun gear} / n _{First planet carrier} =1+zf/Zg, where Zf is the first ring gear number, zg is the first sun gear number, and at this time is the speed-increasing output;

2) When the engine is required to operate in a low gear, the charging load is reduced to enable the generator rotor to idle, and the third gear ring can rotate at the fastest rotating speed. However, because the third gear ring is fixedly connected with the second one-way clutch, the other end of the second one-way clutch is fixedly connected with the first planet carrier, the third gear ring is limited by the second one-way clutch, and the maximum rotating speed of the third gear ring can only synchronously rotate with the first planet carrier, at the moment, the rotating speed of the first sun gear is the same as the rotating speed of the first planet carrier, and the speed ratio i is increased _{First sun gear} = n _{First sun gear} / n _{First planet carrier} =1, at this time, low-speed output;

the transmission ratio of the second planetary gear speed change structure is as follows: because the third gear ring and the first gear ring are in the same body, the third gear ring drives the duplex gear to rotate, the duplex gear drives the second sun gear and the generator rotor to rotate at a speed increasing speed, and the rotating speed of the third gear ring is n _{Third gear ring} The second sun gear has a rotation speed of n _{Second sun gear} Then, the speed ratio i between the third gear ring and the second sun gear is increased _{Generator rotor} = n _{Second sun gear} / n _{Third gear ring} = (1+zb/Za)/(1-ZbZd/ZcZe), where Zb is the second ring gear tooth number, 107 teeth in this embodimentThe method comprises the steps of carrying out a first treatment on the surface of the Za is the number of teeth of the second sun gear, 43 teeth in this embodiment; zc is the number of teeth on the left side of the duplex gear, which is 32 teeth in the embodiment; zd is the number of teeth on the right side of the duplex gear, which is 28 teeth in the embodiment; ze is the third ring gear tooth number, 103 teeth in this embodiment; i of the rotation speed of the generator rotor at the third gear ring _{Generator rotor} And the rotation speed is doubled. The specific number of teeth belongs to the common general knowledge of the person skilled in the art, and is not repeated, at this time, the charging load is controlled to be 0, and the generator rotor idles;

3) When the generator is required to operate between the high gear and the low gear, the charging load is controlled to be between the two extreme point conditions of 1) and 2), and the generator rotor can be operated between the locked-rotor and the idle running state. When the operation of the generator rotor is controlled to be in a locked state, the third gear ring is locked, namely the third gear ring is static and is output in a high-speed gear; when the operation of the generator rotor is controlled to be in an idle state, the maximum rotation speed of the third gear ring and the first planet carrier synchronously rotate, and then the rotation speed of the first sun wheel is the same as the rotation speed of the first planet carrier, so that the output is a low-speed gear; the speed increasing ratio is also between 1+Zf/Zg and 1, zf is the number of teeth of the first gear ring, zg is the number of teeth of the first sun gear, and the desired speed increasing ratio is obtained by adjusting the rotation speeds of the third gear ring and the first gear ring, so that riding is in the most comfortable state.

As shown in fig. 1, the power transmission of the continuously variable center motor has two paths:

1) The manual power transmission path is that a rider treads pedals to drive a middle shaft to rotate, and a left half shaft of the middle shaft transmits power to a torque sensor through a ratchet at the end of the middle shaft and a ratchet wheel (a first one-way clutch) at the end of the torque sensor, so that the power is transmitted to a first planet carrier;

2) The motor power transmission path is that the motor power is transmitted to a motor output shaft and a motor output shaft gear through a motor one-way clutch 22 and further transmitted to a motor power input gear at the first planet carrier end and a first planet carrier through a transition gear;

3) The manual power and the motor power are intersected on the first planet carrier, the manual power and the motor power are output after speed change, so that a rider can ride with the most comfortable force and pedal frequency, and the motor also works in a high-efficiency interval.

The first carrier drives the first planet gears and the first planet gears mesh with the first ring gear and the first sun gear simultaneously. As before, the rotational speed of the first sun gear is determined jointly by the rotational speed of the first planet carrier and the first ring gear, in particular the first sun gear rotational speed n _{First sun gear} = （1+Zf/Zg）* n _{First planet carrier} - Zf/Zg * n _{First gear ring} Zf is the first ring gear tooth number and Zg is the first sun gear tooth number.

Further description will be provided below in connection with the relationship between the specific riding situation and the generator load and the first-second planetary gear shift structure,

1) When a rider starts from a stop state, the rotating speed of the tooth disc output shaft and the first sun gear is 0, the load is large, the first planet carrier pushes the first planet gears, the first planet gears further push the first gear rings to rotate, when the rotating speed of the first gear rings catches up with the rotating speed of the first planet carrier, the ratchet wheels at the end of the first planet carrier are meshed with the ratchet wheels at the end of the gear ring support frame, the first gear rings and the first planet carrier synchronously rotate, at the moment, the speed increasing ratio of the tooth disc output shaft is minimum, the rotating speed ratio of the middle shaft to the tooth disc output shaft is 1:1, namely the speed increasing ratio i=1, and the tooth disc is operated in a low gear. Meanwhile, the first gear ring drives the third gear ring to rotate, the second third planetary gear and the second sun gear are further driven to rotate, the second sun gear is fixedly connected with the generator rotor to drive the generator rotor to rotate, the charging load of the generator is adjusted to 0 at the moment, and the generator rotor idles.

2) When riding on a downhill road or downwind on a flat ground, the bicycle has smaller resistance and the toothed disc requires smaller torque, but requires high rotation speed. At this time, the charging load of the generator is increased, so that the rotation speed of the rotor of the generator is reduced until the rotor is blocked, and then the rotation speed of the third gear ring is also changed into 0, at this time, the speed increasing ratio is maximum, and the rotation speed ratio of the middle shaft to the output shaft of the tooth disc is i=1+zf/zg=1+102/30=4.4, wherein Zf is the number of teeth of the first gear ring, and in the embodiment, is 102 teeth; zg is the number of teeth of the first sun gear, 30 teeth in this embodiment, i.e. the speed increasing ratio i=4.4 of the toothed disc output shaft, operating in high gear. The rider rides faster at a lower pedaling frequency.

3) When riding under the road conditions between the two conditions, the charging load of the generator is controlled, so that the rotating speed of the first gear ring is between the rotating speed of the middle shaft and the rotating speed of the 0, the speed increasing ratio of the output shaft of the tooth disc is also between 1-4.4, and the riding is in the most comfortable state.

As shown in fig. 7, the continuously variable transmission mid-motor further includes a controller 26 and a charging load control unit 27, and during the riding process, riding status signals 26-1 including signals of wheel rotation speed signals, treading moment signals, treading frequency signals, motor rotation speed, generator rotation speed and the like are collected, and the controller outputs corresponding charging load signals 26-2 to the charging load control unit 27 according to the riding status signals, and the purpose of adjusting the speed increasing ratio of the output shaft of the dental disc is achieved by adjusting the charging load to control the first gear ring rotation speed.

The electricity generated by the generator during the speed change process is charged into the battery 28 and recycled, thereby maximizing efficiency.

The foregoing detailed description of a continuously variable transmission center motor with reference to the embodiments is illustrative and not restrictive, and the transmission system of the foregoing embodiments can be applied to other fields of variable transmission besides the field of bicycles, and several embodiments can be listed according to the defined scope, so that it should fall within the protection scope of the present utility model without departing from the general inventive concept.

Claims (5)

1. The utility model provides a put motor in infinitely variable speed, includes casing, helping hand motor, generator, axis and planet wheel variable speed structure, characterized by: the center shaft penetrates through the center of the generator and the planetary gear speed change structure, the center shaft comprises a left half shaft and a right half shaft, the left half shaft (1-1) is connected with a torque sensor (2) through a first one-way clutch, the torque sensor is connected with a first planet carrier (3), the left half shaft is supported on a shell through a left half shaft support bearing (1-6), the right half shaft is connected with the first planet carrier in a sliding manner, a gear ring support frame (9) is supported on the first planet carrier through a first gear ring support frame support bearing (9-2), a first gear ring (6) and a third gear ring (10) which is in common with the first gear ring are fixedly connected on the gear ring support frame, the first gear ring is meshed with the first planet carrier (5), the first planet carrier is supported on a first planet carrier support shaft (4-1) through a first planet carrier support bearing, and the first planet carrier is meshed with a first sun gear (7) to form the first planetary gear speed change structure; the third gear ring is meshed with a right gear (11) of the duplex planet gear, a left gear (11-1) of the duplex planet gear is meshed with a second gear ring (14) fixed on the shell, the left gear is meshed with a third sun gear (15), the duplex planet gear is supported on a duplex planet gear supporting shaft (12) through a duplex planet gear supporting bearing (11-2), the duplex planet gear supporting shaft is supported on a second planet carrier (13), the second planet carrier is supported on a first planet carrier through a second planet carrier supporting bearing (13-1), and the third sun gear is fixedly connected with a generator rotor (16) to form a second planet gear speed change structure; the gear ring support frame is provided with a second one-way clutch with the first planet frame, the shell is provided with an outer circle of a tooth disc output shaft (7-1) through a tooth disc output shaft supporting bearing (7-2), an inner circle of the tooth disc output shaft is supported on a right half shaft (1) of a middle shaft through a sun wheel output shaft supporting bearing (1-5), an input gear (3-2) of the outer circle of the first planet frame is meshed with a transition gear (25), and the transition gear is meshed with an output shaft gear (23-1) of the power-assisted motor.

2. The infinitely variable center motor of claim 1, wherein: the left half shaft of the middle shaft is provided with a middle shaft end ratchet (1-2), and the inner ring of the moment sensor is provided with a moment sensor end ratchet (2-1) to form a first one-way clutch structure.

3. The infinitely variable center motor of claim 1, wherein: the gear ring support frame is provided with a gear ring support frame end ratchet (9-1), and the first planet carrier is provided with an output mechanism planet carrier end ratchet (3-1) to form a second one-way clutch structure.

4. The infinitely variable center motor of claim 1, wherein: the left half shaft and the right half shaft are connected in an inserting mode through a spline.

5. The infinitely variable center motor of claim 1, wherein: rectangular teeth are axially arranged on the end face of the moment sensor and are in key joint with the rectangular teeth on the end face of the first planet carrier.