CN117401079A

CN117401079A - Middle shaft speed changer and middle motor

Info

Publication number: CN117401079A
Application number: CN202311701318.8A
Authority: CN
Inventors: 李激初; 林杰煌; 何煦
Original assignee: Guangdong Lofandi Intelligent Technology Co ltd
Current assignee: Guangdong Lofandi Intelligent Technology Co ltd
Priority date: 2023-09-09
Filing date: 2023-12-12
Publication date: 2024-01-16
Also published as: CN117489761A

Abstract

The invention belongs to the technical field of speed changers, and particularly relates to a middle shaft speed changer and a middle motor. According to the center shaft transmission and the center motor, the gear ring of the planetary gear mechanism is locked or unlocked through the control fixing mechanism, so that the one-way clutch assembly is separated or connected, the center shaft transmission achieves the gear shifting function, and the gear shifting process is better controlled as only a single fixing mechanism is required to be controlled and two fixing mechanisms are not required to be controlled, the gear shifting is rapid, the time interval is extremely short, and the phenomenon of stepping on the air is avoided. The one-way clutch assembly has the advantages that the size of the one-way clutch assembly is far smaller than that of the fixing mechanism, the cost is low, independent control is not needed, and the structure of the intermediate shaft transmission is compact and the size is reduced. The one-way clutch component and the fixing mechanism are arranged on the outer side of the gear ring of the transmission mechanism, so that the processing and the assembly are convenient.

Description

Middle shaft speed changer and middle motor

Technical Field

The invention belongs to the technical field of speed changers, and particularly relates to a middle shaft speed changer and a middle motor.

Background

Ebike is an Electric Bike, also called Electric bicycle, which is a bicycle that uses a battery and an Electric motor to provide auxiliary power. Unlike conventional bicycles, ebike employs a battery and a motor to provide auxiliary power, so that riding is easier and more convenient.

The motor is typically mounted at a location intermediate the wheels or frame and may be supplied with the required electrical energy by a battery. The wheel mounted motor is generally referred to as a rear motor and the mid-frame mounted motor is generally referred to as a center motor. The motor of Ebike adopts a direct current brushless motor and can be divided into 250W, 350W, 500W and the like according to different power levels.

However, the middle motor with the speed change function used by Ebike in the market at present has large volume and serious shift hysteresis, which may cause unsmooth power transmission in the shift process and inconvenience in riding experience.

Accordingly, the prior art is subject to improvement and development.

Disclosure of Invention

The utility model aims to provide a middle shaft transmission and put motor, the structure is compacter, and the speed of shifting is not towered promptly.

In order to solve the technical problems, the middle shaft transmission provided by the application,

a bottom bracket that is rotatably supported to the frame, from which torque is input;

the transmission mechanism is connected with the middle shaft and provided with at least one transmission ratio;

one end of the fixing mechanism is connected with the frame, and the other end of the fixing mechanism is connected with a part of the transmission mechanism;

One end of the one-way clutch component is connected with the frame, and the other end of the one-way clutch component is connected with the other part of the transmission mechanism;

the chain wheel is fixed on the transmission mechanism and outputs torque;

after the torque passes through the transmission mechanism, a part of components of the transmission mechanism are relatively fixed with the frame by controlling the fixing mechanism so as to change the transmission ratio.

Further, the transmission mechanism is a plurality of groups of planetary gear mechanisms.

Further, one end of the fixing mechanism is connected to the frame, and the other end of the fixing mechanism is connected to a gear ring of a part of the transmission mechanism.

Further, one end of the one-way clutch assembly is connected with the frame, and the other end of the one-way clutch assembly is connected with a gear ring of another part of transmission mechanism.

Further, the transmission mechanism is at least one of speed reduction transmission and speed increase transmission.

Further, the transmission mechanism is a compound transmission which is subjected to speed increasing transmission and then speed reducing transmission.

Further, the transmission mechanism includes:

a seventh set of planetary gear mechanisms including a seventh planetary gear and a seventh ring gear, the seventh ring gear being intermeshed with the seventh planetary gear;

an eighth set of planetary gear mechanisms including an eighth sun gear, an eighth planetary gear, and an eighth ring gear, the eighth planetary gear being externally meshed with the eighth sun gear, the eighth ring gear being internally meshed with the eighth planetary gear;

A ninth group of planetary gear mechanisms including a ninth sun gear, a ninth planetary gear and a ninth ring gear, the ninth planetary gear being externally meshed with the ninth sun gear, the ninth ring gear being internally meshed with the ninth planetary gear;

a tenth group of planetary gear mechanisms including a tenth planetary gear and a tenth ring gear, the tenth ring gear being internally meshed with the tenth planetary gear;

an eleventh group of planetary gear mechanisms including an eleventh planetary gear and an eleventh ring gear, the eleventh ring gear being in internal mesh with the eleventh planetary gear;

a twelfth set of planetary gear mechanisms including a twelfth sun gear, twelfth planetary gears, and a twelfth ring gear, the twelfth planetary gears being externally meshed with the twelfth sun gear, the twelfth ring gear being internally meshed with the twelfth planetary gears;

the seventh planetary gear, the eighth planetary gear, the ninth planetary gear and the tenth planetary gear are hinged on the first planetary frame, the ninth planetary gear and the tenth planetary gear are hinged on the second planetary frame, the seventh planetary gear and the eighth planetary gear set are combined into a duplex planetary gear, the ninth planetary gear and the tenth planetary gear set are combined into a duplex planetary gear, and the eleventh planetary gear and the twelfth planetary gear set are combined into a duplex planetary gear;

The eighth sun gear, the ninth sun gear and the twelfth sun gear are combined into a triple sun gear, and the triple sun gear is integrally sleeved on the middle shaft in a cylindrical shape and can rotate relative to the middle shaft;

one end of the second planet carrier is fixedly connected with the chain wheel.

Further, one end of the fixing mechanism is connected to the frame, the other end of the fixing mechanism is connected to the eighth gear ring, the ninth gear ring, the tenth gear ring and the eleventh gear ring respectively, one end of the one-way clutch assembly is connected to the frame, and the other end of the one-way clutch assembly is connected to the seventh gear ring and the twelfth gear ring respectively.

Further, the transmission mechanism includes:

a first set of planetary gear mechanisms including a first sun gear, a first ring gear, a first planet gear, the first planet gear being in external engagement with the first sun gear, the first ring gear being in internal engagement with the first planet gear;

a second set of planetary gear mechanisms including a second sun gear, a second ring gear, and a second planetary gear, the second planetary gear being in external engagement with the second sun gear, the second ring gear being in internal engagement with the second planetary gear;

the first planetary gear and the second planetary gear are hinged on the first planet carrier;

the first sun gear and the second sun gear are fixedly connected with the middle shaft;

The first planet carrier is rotatably supported on the center shaft and one end of the first planet carrier is fixedly connected with the sprocket.

Further, one end of the fixing mechanism is connected to the frame, the other end of the fixing mechanism is connected to the first gear ring, one end of the one-way clutch assembly is connected to the frame, and the other end of the one-way clutch assembly is connected to the second gear ring.

Further, the transmission mechanism includes:

a third group of planetary gear mechanisms, comprising a third gear ring and a third planetary gear, wherein the third gear ring is internally meshed with the third planetary gear;

a fourth set of planetary gear mechanisms including a fourth sun gear, a fourth ring gear, and a fourth planetary gear, the fourth planetary gear being in external engagement with the fourth sun gear and the fourth ring gear being in internal engagement with the fourth planetary gear;

The first planetary gear, the second planetary gear, the third planetary gear and the fourth planetary gear are hinged on a first planetary carrier, and the third planetary gear and the fourth planetary gear set form a first duplex planetary gear;

the fourth sun gear is rotatably supported on the central shaft and one end of the fourth sun gear is fixedly connected with the sprocket.

Further, one end of the fixing mechanism is connected to the frame, the other end of the fixing mechanism is connected to the first gear ring and the fourth gear ring respectively, one end of the one-way clutch assembly is connected to the frame, and the other end of the one-way clutch assembly is connected to the second gear ring and the third gear ring respectively.

Further, the transmission mechanism further comprises:

a fifth group of planetary gear mechanisms comprising a fifth sun gear, a fifth ring gear and a fifth planetary gear, wherein the fifth planetary gear is externally meshed with the fifth sun gear, and the fifth ring gear is internally meshed with the fifth planetary gear;

a sixth set of planetary gear mechanisms including a sixth ring gear, a sixth planetary gear, the sixth ring gear being intermeshed with the sixth planetary gear;

the first planetary gear, the second planetary gear, the third planetary gear, the fourth planetary gear, the fifth planetary gear and the sixth planetary gear are hinged on a first planetary carrier, the third planetary gear and the fourth planetary gear set form a first duplex planetary gear, and the fifth planetary gear and the sixth planetary gear set form a second duplex planetary gear;

The fourth sun gear and the fifth sun gear are combined into a duplex sun gear;

the fourth sun gear and the fifth sun gear are rotatably supported on the center shaft and fixedly connected with the sprocket at one end.

Further, one end of the fixing mechanism is connected to the frame, the other end of the fixing mechanism is connected to the first gear ring, the fourth gear ring, the fifth gear ring and the sixth gear ring respectively, one end of the one-way clutch assembly is connected to the frame, and the other end of the one-way clutch assembly is connected to the second gear ring and the third gear ring respectively.

The application also provides a centrally-mounted motor, which comprises the middle shaft transmission and a motor, wherein the motor is connected with the middle shaft or the transmission mechanism.

Further, the motor is coaxially arranged with the center shaft.

Further, the motor and the center shaft are arranged in parallel with each other along the axis.

Further, the motor and the center shaft are arranged in a mutually perpendicular axis.

Further, the motor is connected with the middle shaft or the transmission mechanism through any one of chain transmission, belt transmission and gear transmission.

The middle shaft speed changer and the middle motor lock or loosen the gear ring of the planetary gear mechanism by controlling the fixing mechanism, so that the one-way clutch assembly is separated or connected, and the middle shaft speed changer realizes the gear shifting function. The one-way clutch assembly has the advantages that the size of the one-way clutch assembly is far smaller than that of the fixing mechanism, the cost is low, independent control is not needed, and the structure of the intermediate shaft transmission is compact and the size is reduced. The one-way clutch component and the fixing mechanism are arranged on the outer side of the gear ring of the transmission mechanism, so that the processing and the assembly are convenient.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the application. The objectives and other advantages of the application will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings.

Drawings

FIG. 1 is a schematic structural view of a bottom bracket derailleur embodiment 1 of the present application.

FIG. 2 is a first gear power transmission path diagram of the bottom bracket transmission embodiment 1 of the present application.

Fig. 3 is a second gear power transmission path diagram of the bottom bracket transmission embodiment 1 of the present application.

Fig. 4 is a schematic structural view of embodiment 2 of the bottom bracket transmission of the present application.

Fig. 5 is a first gear power transmission path diagram of the bottom bracket transmission embodiment 2 of the present application.

FIG. 6 is a second gear power transmission path diagram of the bottom bracket transmission embodiment 2 of the present application.

Fig. 7 is a third gear power transmission path diagram of the bottom bracket transmission embodiment 2 of the present application.

Fig. 8 is a fourth gear power transmission path diagram of the bottom bracket transmission embodiment 2 of the present application.

Fig. 9 is a schematic structural view of embodiment 3 of the bottom bracket transmission of the present application.

FIG. 10 is a first gear power transmission path diagram of the bottom bracket transmission embodiment 3 of the present application.

FIG. 11 is a second gear power transmission path diagram of the bottom bracket transmission embodiment 3 of the present application.

FIG. 12 is a third gear power transmission path diagram of the bottom bracket transmission embodiment 3 of the present application.

Fig. 13 is a fourth gear power transmission path diagram of the bottom bracket transmission embodiment 3 of the present application.

FIG. 14 is a fifth gear power transmission path diagram of the bottom bracket transmission embodiment 3 of the present application.

FIG. 15 is a sixth gear power transmission path diagram of the bottom bracket transmission embodiment 3 of the present application.

FIG. 16 is a seventh gear power transmission path diagram of the bottom bracket transmission embodiment 3 of the present application.

Fig. 17 is a power transmission path diagram of the eighth gear of the bottom bracket transmission embodiment 3 of the present application.

Fig. 18 is a schematic structural view of embodiment 4 of the center motor in the present application.

Fig. 19 is a schematic structural view of embodiment 5 of the center motor in the present application.

Fig. 20 is a schematic structural view of embodiment 6 of the central motor in the present application.

Fig. 21 is a schematic structural view of embodiment 7 of the center motor in the present application.

Fig. 22 is a schematic structural view of embodiment 8 of the center motor in the present application.

Fig. 23 is a schematic structural view of a bottom bracket transmission embodiment 9 of the present application.

Fig. 24 is a power transmission path diagram of a bottom bracket transmission embodiment 9 of the present application.

Fig. 25 is a perspective view of embodiment 9 of the bottom bracket transmission of the present application.

Fig. 26 is a front view of a bottom bracket transmission embodiment 9 of the present application.

FIG. 27 is a longitudinal cross-sectional view of a bottom bracket transmission embodiment 9 of the present application.

Fig. 28 is a perspective view of embodiment 9 of a bottom bracket transmission (electric shift mechanism) of the present application.

Fig. 29 is a perspective view of the securing mechanism of the present application.

Fig. 30 is a front view of the securing mechanism of the present application.

FIG. 31 is a cross-sectional view taken along lines A-A, B-B, C-C, and D-D of FIG. 30.

Fig. 32 is a perspective view of a bottom bracket derailleur (manual shift mechanism) embodiment 10 of the present application.

Fig. 33 is a perspective view of an embodiment 10 of a bottom bracket derailleur (manual shift mechanism with fixed disk hidden) of the present application.

Fig. 34 is a schematic structural view of the embodiment 10 of the central motor in the present application.

Fig. 35 is a perspective view of one of the embodiments 10 of the central motor of the present application.

Fig. 36 is a second perspective view of the embodiment 10 of the central motor of the present application.

Fig. 37 is a third perspective view of the embodiment 10 of the central motor of the present application.

Fig. 38 is a perspective view of the center motor embodiment 10 of the present application.

Description of the reference numerals:

1-a middle shaft, wherein the middle shaft is provided with a plurality of grooves,

2-transmission mechanism, 20-first carrier, 200-second carrier, 21-first set of planetary gear mechanism, 211-first sun gear, 212-first planetary gear, 213-first ring gear, 22-second set of planetary gear mechanism, 221-second sun gear, 222-second planetary gear, 223-second ring gear, 23-third set of planetary gear mechanism, 232-third planetary gear, 233-third ring gear, 24-fourth set of planetary gear mechanism, 241-fourth sun gear, 242-fourth planetary gear, 243-fourth ring gear, 25-fifth set of planetary gear mechanism, 251-fifth sun gear, 252-fifth planetary gear, 253-fifth ring gear, 26-sixth set of planetary gear mechanism, 262-sixth planetary gear, 263-sixth ring gear, 27-seventh set of planetary gear mechanism, 272-seventh planetary gear, 273-seventh ring gear, 28-eighth set of planetary gear mechanism, 281-eighth sun gear, 282-eighth planetary gear, 283-eighth ring gear, 2831-eighth ratchet slot, 29-ninth set of planetary gear mechanism, 291-ninth sun gear, 292-ninth planetary gear, 293-ninth ring gear, 2931-ninth ratchet slot, 2100-tenth set of planetary gear mechanism, 21002-tenth planetary gear, 21003-tenth ring gear, 210031-tenth ratchet slot, 2110-eleventh set of planetary gear mechanism, 21102-eleventh planetary gear, 21103-eleventh ring gear, 211031-eleventh ratchet slot, 2120-twelfth set of planetary gearing, 21201-twelfth sun gear, 21202-twelfth planetary gearing, 21203-twelfth ring gear,

3-fixing means, 31-first fixing means, 311-first control pawl, 312-first control cam, 3121-first control slot, 32-second fixing means, 321-second control pawl, 322-second control cam, 3221-second control slot, 33-third fixing means, 331-third control pawl, 332-third control cam, 3321-third control slot, 34-fourth fixing means, 341-fourth control pawl, 342-fourth control cam, 3421-fourth control slot, 35-housing, 351-dodging slot, 352-spindle, 36-camshaft, 37-electric shift mechanism, 371-drive, 372-first reduction mechanism, 373-buffer, 374-gear feedback device, 38-manual shift mechanism, 381-fixed disk, 382-spool, 383-rotating disk, 3831-wire slot, 384-control wire,

4-one-way clutch assembly, 41-first one-way clutch assembly, 42-second one-way clutch assembly, 5-sprocket, 6-frame, 7-motor, 71-stator, 72-rotor, 8-second reduction mechanism, 81-first reduction gear, 82-second reduction gear, 83-third reduction gear, 9-crank, 10-protective housing.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present invention and are not to be construed as limiting the present invention.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "above" or "below" a second feature may include both the first and second features being in direct contact, as well as the first and second features not being in direct contact but being in contact with each other through additional features therebetween. Moreover, a first feature being "above," "over" and "on" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicating that the first feature is higher in level than the second feature. The first feature being "under", "below" and "beneath" the second feature includes the first feature being directly under and obliquely below the second feature, or simply means that the first feature is less level than the second feature.

The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the invention. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present invention provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

The utility model provides a bottom in the middle of the frame 6 of vehicle of axis transmission fixed mounting, axis transmission includes axis 1, drive mechanism 2, fixed establishment 3, one-way clutch subassembly 4 and sprocket 5, wherein the both ends of axis 1 are fixed connection crank 9 respectively, crank 9 swivelling joint is pedal, the person of riding is through trampling the moment of torsion that will produce and is transmitted to axis 1, input drive mechanism 2 by axis 1 again, drive mechanism 2 is used for adjusting transmission ratio and output rotational speed, realize the switching of different gear through the meshing relationship of changing different planetary gears, sprocket 5 is fixed on drive mechanism 2 for with moment of torsion output, sprocket 5 rethread chain drive or belt drive is with moment of torsion input to the flywheel on, drive the rear wheel rotation of vehicle.

The device can be used for bicycles, folding bicycles, ebike, electric power-assisted bicycles, electric vehicles, electric motorcycles, cargo electric vehicles, tricycles, scooters, electric scooters and other vehicles.

Fig. 1 shows a schematic diagram of the structure of the axial transmission of the present application, wherein the transmission mechanism 2 comprises a plurality of groups of planetary gear mechanisms, and the planetary gear mechanism is a simple gear transmission mechanism 2, and the fixed shaft gear mechanism is composed of two or more gears. The gears are mounted on a fixed shaft and transmit power and torque through the engagement between the gears. The planetary gear mechanism is a complex gear mechanism 2, and is composed of three basic components: sun gears, planet gears, and ring gears. The sun gear is centered and the planet gears rotate about the sun gear and mesh with the ring gear. By changing the position and the motion state of the planetary gears, different speed ratios, torque conversion and reverse transmission can be realized. The planetary gear transmission has smaller volume and lower height, can realize large torque transmission in a limited space, and is particularly suitable for occasions needing high torque and compact design. The bicycle has high requirement on space utilization rate of parts, and the operability of a rider can be influenced by larger size of the parts, so that the overall dimension of the whole middle shaft transmission can be greatly reduced by adopting the planetary gear mechanism.

Example 1

In the present embodiment, two sets of planetary gear mechanisms are employed, specifically including a first set of planetary gear mechanisms 21 and a second set of planetary gear mechanisms 22. The connection relation and the meshing relation of all parts of the planetary gear mechanism are as follows:

the first group planetary gear mechanism 21 includes a first sun gear 211, a first ring gear 213, and a first planetary gear 212, the first planetary gear 212 is externally meshed with the first sun gear 211, and the first ring gear 213 is internally meshed with the first planetary gear 212;

the second group of planetary gear mechanisms 22 includes a second sun gear 221, a second ring gear 223, and second planetary gears 222, the second planetary gears 222 being in external engagement with the second sun gear 221, the second ring gear 223 being in internal engagement with the second planetary gears 222;

the first planetary gear 212 and the second planetary gear 222 are hinged on the same carrier, i.e., the first carrier 20;

the first sun gear 211 and the second sun gear 221 are fixedly connected with the middle shaft 1;

the first carrier 20 is rotatably supported on the bottom bracket 1 and has one end fixedly connected to the sprocket 5.

In the present embodiment, the gear ratio is changed using two sets of planetary gear mechanisms, and the ring gear of the planetary gear mechanisms is locked or unlocked using the fixing mechanism 3.

The fixing mechanism 3 can be any mechanism capable of enabling the gear ring to be stationary from rotary motion, such as a ratchet pawl mechanism, a brake mechanism, a lock pin mechanism and the like, one end of the fixing mechanism 3 is connected with the frame 6, the other end of the fixing mechanism 3 is connected with a part of the transmission mechanism 2, and in a normal state, the fixing mechanism 3 is in a non-working state, namely the gear ring can rotate relative to the middle shaft 1, after the fixing mechanism 3 works, the gear ring is fixed relative to the frame 6, and the gear ring cannot rotate.

The fixing mechanism 3 can be provided with one or a plurality of gear rings of the first group of planetary gear mechanisms 21 and the second group of planetary gear mechanisms 22, and the gear rings can be fixed by the single fixing mechanism 3, so that the transmission ratio can be changed, but in the gear shifting process, the gear shifting is rapid, the dragging is avoided, the time for switching the two fixing mechanisms 3 is required to be controlled to be small, however, the requirements on the fixing mechanisms 3 and a controller and a control system for controlling the fixing mechanisms are high, and the realization is difficult or the manufacturing cost is high.

In order to simplify the gear shift control of the bottom bracket transmission and to reduce the volume of the bottom bracket transmission, a one-way clutch assembly 4 is provided instead of a fastening mechanism 3. The one-way clutch assembly 4 allows rotation of the part in one direction and prevents rotation in the other direction.

The one-way clutch assembly 4 is arranged on the outer side of the gear ring of the transmission mechanism 2, one end of the one-way clutch assembly is connected with the frame 6, and the other end of the one-way clutch assembly is connected with the gear ring of the transmission mechanism 2. In normal conditions, the allowed rotation direction of the one-way clutch assembly 4 is opposite to the rotation direction of the ring gear, i.e. the ring gear is stopped by the one-way clutch assembly 4 from being stationary in the direction of the disallowed rotation. The one-way clutch assembly 4 may employ a roller clutch, a sprag clutch, a pawl clutch, a friction clutch, an electromagnetic clutch, or the like.

Assuming that the number of teeth of the first sun gear 211 is z1, the number of teeth of the first ring gear 213 is z2, the number of teeth of the first planetary gear 212 is z3, the number of teeth of the second sun gear 221 is z4, the number of teeth of the second ring gear 223 is z5, the number of teeth of the second planetary gear 222 is z6, the number of teeth of the third ring gear 233 is z7, the number of teeth of the third planetary gear 232 is z8, the number of teeth of the fourth sun gear 241 is z9, the number of teeth of the fourth ring gear 243 is z10, and the number of teeth of the fourth planetary gear 242 is z11.

Fig. 2 shows a power transmission path diagram of the first gear of the axial transmission embodiment 1 of the present application.

As shown in the drawing, at this time, the first fixing mechanism 31 is in the inactive state, the torque generated by the rider stepping on is input from the bottom bracket 1, and since the first ring gear 213 is not fixed, the first ring gear 213 is in the idle state and does not output torque outwards, corresponding to the failure of the first group planetary gear mechanism 21, according to the transmission characteristics of the planetary gears. And the one-way clutch assembly 4 is arranged in a direction that can prevent the second ring gear 223 from rotating, i.e., the one-way clutch assembly 4 is engaged to fix the second ring gear 223 to the frame 6. The movement states of the second group planetary gear mechanism 22 at this time are: the second sun gear 221 is driven, the second ring gear 223 is fixed, and the first carrier 20 is driven, at this time, in a reduction gear, i1= (z4+z5)/z 4.

Fig. 3 shows a power transmission path diagram of the second gear of the bottom bracket transmission embodiment 1 of the present application.

As shown in the drawing, the first fixing mechanism 31 is in an operating state at this time, i.e., the first ring gear 213 is fixed by the first fixing mechanism 31, the torque generated by the stepping of the rider is input from the center shaft 1, the first sun gear 211 is input according to the transmission characteristics of the planetary gears, the first ring gear 213 is fixed, the first carrier 20 is output, since the number of teeth of the first ring gear 213 is the same as the number of teeth of the second ring gear 223, and the number of teeth of the first sun gear 211 is larger than the number of teeth of the second sun gear 221, according to the equation of the motion characteristics of the planetary gear mechanism,

n1+an2=(1+a)n3，a=z2/z1

where n1 is the rotational speed of the sun gear, n2 is the rotational speed of the ring gear, n3 is the rotational speed of the carrier, z1 is the number of teeth of the sun gear, z2 is the number of teeth of the ring gear, and z3 is the number of teeth of the first carrier 20.

By calculation, the rotational speed of the first carrier 20 in the second gear is greater than the rotational speed of the first carrier 20 in the first gear, the rotational speed of the first carrier 20 is input to the second set of planetary gear mechanisms 22, the rotational speed of the second sun gear 221 is always kept unchanged according to the equation of motion characteristics, the rotational speed of the first carrier 20 increases, the rotational speed of the second ring gear 223 is increased and is not zero, and the rotational direction of the second ring gear 223 is the same as the rotational direction of the second sun gear 221, at this time, the first one-way clutch assembly 41 is in a disengaged state, and the second set of planetary gear mechanisms 22 is disabled accordingly. The same is true below, and will not be described again.

According to the calculation formula i= (z1+z2)/z 1 of the gear ratio, the number of teeth of the first ring gear 213 is the same as the number of teeth of the second ring gear 223, and the number of teeth of the first sun gear 211 is larger than the number of teeth of the second sun gear 221, so that the gear ratio of the second gear is smaller than that of the first gear but larger than 1, and the gear ratio is a reduction gear. I2= (z1+z2)/z 1 is obtained.

From the above, the gear ring of the planetary gear mechanism is locked or unlocked by controlling the fixing mechanism 3, so that the one-way clutch assembly 4 is separated or jointed, the middle shaft transmission is switched from the first gear to the second gear, and the gear shifting function is realized, and as only a single fixing mechanism 3 is required to be controlled and two fixing mechanisms 3 are not required to be controlled, the gear shifting process is better controlled, the gear shifting is rapid, the time interval is extremely short, and the phenomenon of stepping down is avoided. The one-way clutch assembly 4 has a volume far smaller than that of the fixing mechanism 3, is low in cost and does not need to be controlled independently, so that the structure of the countershaft transmission is compact and the volume is reduced. The one-way clutch assembly 4 and the fixing mechanism 3 are arranged on the outer side of the gear ring of the transmission mechanism 2, so that the processing and the assembly are convenient.

Example 2

Fig. 4 shows a schematic configuration of embodiment 2, which differs from embodiment 1 in that a third group of planetary gear mechanisms 23 and a fourth group of planetary gear mechanisms 24 are added, more gears can be provided, and the manner of torque output is different.

The connection relation and the meshing relation of all parts of the planetary gear mechanism are as follows:

the third group of planetary gear mechanisms 23 comprises a third gear ring 233 and third planetary gears 232, and the third gear ring 233 is internally meshed with the third planetary gears 232;

the fourth group of planetary gear mechanisms 24 includes a fourth sun gear 241, a fourth ring gear 243, and fourth planetary gears 242, the fourth planetary gears 242 being in external engagement with the fourth sun gear 241, the fourth ring gear 243 being in internal engagement with the fourth planetary gears 242;

the first planetary gear 212, the second planetary gear 222, the third planetary gear 232 and the fourth planetary gear 242 are hinged on the same planetary carrier, namely the first planetary carrier 20, and the third planetary gear 232 and the fourth planetary gear 242 are combined into a first duplex planetary gear;

the fourth sun gear 241 is rotatably supported on the bottom bracket 1 and has one end fixedly connected to the sprocket 5.

In the present embodiment, the transmission ratio is changed using four sets of planetary gear mechanisms, and the ring gear of the planetary gear mechanisms is locked or unlocked using the fixing mechanism 3. The fixing mechanism 3 is provided with two groups, namely a first fixing mechanism 31 and a second fixing mechanism 32, the one-way clutch assembly 4 is also provided with two groups, namely a first one-way clutch assembly 41 and a second one-way clutch assembly 42, specifically, the first fixing mechanism 31 is arranged outside the first gear ring 213, the first one-way clutch assembly 41 is arranged outside the second gear ring 223, the second one-way clutch assembly 42 is arranged outside the third gear ring 233, and the second fixing mechanism 32 is arranged outside the fourth gear ring 243.

The torque of example 1 is input from the sun gear, output from the first carrier 20, and is simply a reduction gear, whereas the torque of example 2 is input from the sun gear, output from the first carrier 20, input from the first carrier 20, and output from the sun gear, and is a compound gear of a reduction gear and a speed-increasing gear. In practice, the bottom bracket bearing transmission may be a compound transmission of speed increasing transmission and speed reducing transmission, that is, the planetary gear mechanism of the previous stage and the planetary gear mechanism of the next stage are exchanged, and the specific transformation process belongs to a technical scheme easily conceived by those skilled in the art, and is not described herein again.

Fig. 5 shows a power transmission path diagram of the first gear of the bottom bracket transmission embodiment 2 of the present application.

As shown in the drawing, at this time, the first fixing mechanism 31 and the second fixing mechanism 32 are in the inactive state, the first one-way clutch assembly 41 and the second one-way clutch assembly 42 are in the engaged state, and the torque generated by the stepping of the rider is input from the bottom bracket 1, and the first ring gear 213 and the fourth ring gear 243 are not fixed, so that the first ring gear 213 and the fourth ring gear 243 are in the idle state and do not output torque according to the transmission characteristics of the planetary gears, which corresponds to the failure of the first planetary gear mechanism 21 and the fourth planetary gear mechanism 24. And the one-way clutch assembly 4 is arranged in a direction capable of preventing the second ring gear 223 and the fourth ring gear 243 from rotating, that is, the first one-way clutch assembly 41 is engaged to fix the second ring gear 223 to the frame 6, and the second one-way clutch assembly 42 is engaged to fix the third ring gear 233 to the frame 6. The movement states of the second group planetary gear mechanism 22 at this time are: the second sun gear 221 is driven, the second ring gear 223 is fixed, the first planet carrier 20 is driven, and at this time, for speed reduction transmission, the movement states of the third group of planetary gear mechanisms 23 are as follows: the first carrier 20 is driven, the third ring gear 233 is fixed, and the fourth sun gear 241 is driven in NW transmission type (2Z-X mechanism), which is speed increasing transmission in this case, i3=i1×1/{1+ (z7×z11)/(z9×z8) }.

Fig. 6 shows a power transmission path diagram of the second gear of the bottom bracket transmission embodiment 2 of the present application.

As shown in the drawing, at this time, the first fixing mechanism 31 is in the inactive state, the second fixing mechanism 32 is in the active state, that is, the fourth ring gear 243 is fixed by the second fixing mechanism 32, the first one-way clutch assembly 41 is in the engaged state, and the second one-way clutch assembly 42 is in the disengaged state. The torque generated by the stepping of the rider is input from the bottom bracket 1, and the first ring gear 213 and the third ring gear 233 are in the idle state according to the transmission characteristics of the planetary gears, and do not output torque, which corresponds to failure of the first group planetary gear mechanism 21 and the third group planetary gear mechanism 23.

The movement states of the second group planetary gear mechanism 22 at this time are: the second sun gear 221 is driven, the second ring gear 223 is fixed, the first planet carrier 20 is driven, and at this time, for speed reduction transmission, the motion states of the fourth group of planetary gear mechanisms 24 are as follows: the first carrier 20 is driven, the fourth ring gear 243 is fixed, and the fourth sun gear 241 is driven, at this time, i4=i1×z9/(z9+z10) for speed increasing transmission.

Fig. 7 shows a power transmission path diagram of the third gear of the center shaft transmission embodiment 2 of the present application.

As shown in the drawing, at this time, the first fixing mechanism 31 is in an operating state, the second fixing mechanism 32 is in a non-operating state, that is, the first gear ring 213 is fixed by the first fixing mechanism 31, the first one-way clutch assembly 41 is in a disengaged state, the second one-way clutch assembly 42 is in an engaged state, the torque generated by stepping on by the rider is input from the bottom bracket 1, and according to the transmission characteristics of the planetary gears, the second gear ring 223 and the fourth gear ring 243 are in an idling state and do not output torque, which is equivalent to failure of the second planetary gear mechanism 22 and the fourth planetary gear mechanism 24.

The movement states of the first group planetary gear mechanism 21 at this time are: the first sun gear 211 is driven, the first ring gear 213 is fixed, the first carrier 20 is driven, and at this time, for reduction transmission, the movement states of the third group of planetary gear mechanisms 23 are as follows: the first carrier 20 is driving, the third ring gear 233 is fixed, and the fourth sun gear 241 is driven, at this time, i5=i2×1/{1+ (z7×z11)/(z9×z8) }, for speed-increasing transmission.

Fig. 8 shows a power transmission path diagram of the fourth gear of the center shaft transmission embodiment 2 of the present application.

As shown in the drawing, at this time, both the first fixing mechanism 31 and the second fixing mechanism 32 are in an operating state, i.e., the first ring gear 213 is fixed by the first fixing mechanism 31, the fourth ring gear 243 is fixed by the second fixing mechanism 32, and the first one-way clutch assembly 41 and the second one-way clutch assembly 42 are in a disengaged state. The torque generated by the rider stepping on the pedal is input from the bottom bracket 1, and the second ring gear 223 and the third ring gear 233 are in the idle state according to the transmission characteristics of the planetary gears, and do not output torque, which corresponds to failure of the second group planetary gear mechanism 22 and the third group planetary gear mechanism 23.

The movement states of the first group planetary gear mechanism 21 at this time are: the first sun gear 211 is driven, the first ring gear 213 is fixed, the first planet carrier 20 is driven, and at this time, for reduction transmission, the motion states of the fourth group of planetary gear mechanisms 24 are as follows: the first carrier 20 is driven, the fourth ring gear 243 is fixed, and the fourth sun gear 241 is driven, at this time, i6=i2×z9/(z9+z10) for speed increasing transmission.

Example 3

Fig. 9 shows a schematic structural diagram of embodiment 3, which differs from embodiment 2 in that a fifth group of planetary gear mechanisms 25 and a sixth group of planetary gear mechanisms 26 are added to provide further gears.

A fifth group of planetary gear mechanisms 25 including a fifth sun gear 251, a fifth ring gear 253, and a fifth planetary gear 252, the fifth planetary gear 252 being externally meshed with the fifth sun gear 251, the fifth ring gear 253 being internally meshed with the fifth planetary gear 252;

a sixth group of planetary gear mechanisms 26 including a sixth ring gear 263, sixth planetary gears 262, the sixth ring gear 263 being in internal mesh with the sixth planetary gears 262;

the first planetary gear 212, the second planetary gear 222, the third planetary gear 232, the fourth planetary gear 242, the fifth planetary gear 252 and the sixth planetary gear 262 are hinged on the same planetary carrier, namely the first planetary carrier 20, the third planetary gear 232 and the fourth planetary gear 242 are combined into a first duplex planetary gear, and the fifth planetary gear 252 and the sixth planetary gear 262 are combined into a second duplex planetary gear;

the fourth sun gear 241 and the fifth sun gear 251 are combined into a double sun gear;

the fourth sun gear 241 and the fifth sun gear 251 are rotatably supported on the bottom bracket 1 and fixedly connected at one end to the sprocket 5.

One end of the fixing mechanism 3 is connected to the frame 6, the other end is connected to the gear ring, specifically, the fixing mechanism 3 includes a first fixing mechanism 31, a second fixing mechanism 32, a third fixing mechanism 33 and a fourth fixing mechanism 34, one end of the first fixing mechanism 31 is connected to the frame 6, the other end is connected to the first gear ring 213, one end of the second fixing mechanism 32 is connected to the frame 6, the other end is connected to the fourth gear ring 243, one end of the third fixing mechanism 33 is connected to the frame 6, the other end is connected to the fifth gear ring 253, one end of the fourth fixing mechanism 34 is connected to the frame 6, and the other end is connected to the sixth gear ring 263. One end of the one-way clutch assembly 4 is connected to the frame 6, the other end is connected to another part of the gear ring, the one-way clutch assembly 4 specifically comprises a first one-way clutch assembly 41 and a second one-way clutch assembly 42, one end of the first one-way clutch assembly 41 is connected to the frame 6, the other end is connected to the second gear ring 223, one end of the second one-way clutch assembly 42 is connected to the frame 6, and the other end is connected to the third gear ring 233.

As shown in fig. 10-17, the power transmission path of the embodiment 3 has eight gears, and the transmission manner is not substantially different from that of the embodiment 2, and is not repeated, and it should be noted that the third, fourth, fifth and sixth sets of planetary gear mechanisms 26 are all speed-increasing transmission, so that only one-way clutch assembly 4 can be provided, and a plurality of one-way clutch assemblies 4 cannot be provided, otherwise, the first planetary carrier 20 can interfere with each other, so that alternating stress is generated, and vibration, abnormal noise, even cracks and plastic deformation of the bottom bracket transmission are caused.

Example 4

The application also provides a centrally-mounted motor which comprises the middle shaft transmission, so that the centrally-mounted motor has a gear shifting function and an electric boosting function. As shown in fig. 18, the difference from embodiment 1 is that a motor 7 and a second reduction mechanism 8 are added, in this embodiment, the motor 7 is connected to the transmission mechanism 2, specifically, the axis of the output shaft of the motor 7 is parallel to the axis of the central shaft 1, the motor 7 is connected to the first carrier 20 of the transmission mechanism 2 through the second reduction mechanism 8, the second reduction mechanism 8 may be a driving cylindrical gear with small number of teeth and a driven cylindrical gear with large number of teeth, which are meshed with each other, the driving cylindrical gear is mounted on the output shaft of the motor 7, and the driven cylindrical gear is mounted on the outer peripheral surface of the first carrier 20 or directly processes the teeth on the outer peripheral surface of the first carrier 20.

When the motor 7 works, besides the torque stepped on by a rider, the torque generated by the motor 7 is also output to the chain wheel 5 after the torque and the torque are overlapped, so that the rider can obtain higher riding speed or longer riding distance in a labor-saving riding mode.

The bottom bracket transmissions of embodiments 1-3 can all obtain electric assistance by means of the connection of the motor 7.

In put motor with function of shifting, compare with the rear-mounted motor (in-wheel motor) that has the function of shifting, because the structure of variable speed is not in the rear wheel and on frame 6, the road surface that is rugged is impacted and can not be directly passed through wheel rim, spoke and is transmitted wheel hub, still need through the transmission of frame 6, frame 6 has certain effect of absorbing vibrations, has cut down impact force greatly, is difficult to receive external force relatively, is difficult to collide with, makes put motor more durable.

The weight of the rear motor is concentrated on the rear wheel, which is not beneficial to the emptying and jumping of the vehicle, while the weight of the middle motor is concentrated on the position of the lower gravity center of the frame, so that the balance influence on the whole vehicle is small, and the control performance can be greatly improved.

Example 5

Fig. 19 shows a schematic structural diagram of an embodiment 5 of a motor in the present application, which is different from embodiment 4 in that the motor 7 is connected to the central shaft 1 through a second reduction mechanism 8, and the second reduction mechanism 8 may be a driving cylindrical gear with small tooth number and a driven cylindrical gear with large tooth number which are meshed with each other externally, the driving cylindrical gear is mounted on an output shaft of the motor 7, and the driven cylindrical gear is mounted on an outer peripheral surface of the central shaft 1 or directly processes gear teeth on an outer peripheral surface of the central shaft 1, as in embodiment 4. The effect of electric assistance can also be achieved.

The second speed reducing mechanism 8 is one of gear transmission, and the second speed reducing mechanism 8 may be a chain transmission, a belt transmission, or the like.

It is noted that the second reduction mechanism 8 may be disposed at a position close to the sprocket 5 or a position distant from the sprocket 5, as the case may be.

Example 6

Fig. 20 shows a schematic structural diagram of an embodiment 6 of the motor in the present application, which is different from embodiment 5 in that the shaft of the motor 7 is perpendicular to the central shaft 1, for this purpose, the second reduction mechanism 8 adopts a bevel gear, a driving bevel gear with small tooth number is installed on the output shaft of the motor 7, and a driven bevel gear with large tooth number is installed on the outer peripheral surface of the central shaft 1 or directly machining gear teeth on the outer peripheral surface of the central shaft 1.

Example 7

Fig. 21 shows a schematic structural diagram of a central motor embodiment 7 in the present application, which is different from embodiment 4 in that the motor 7 is split into main parts such as a stator 71 and a rotor 72, and the motor 7 is disposed inside the first planet carrier 20, and the motors 7 of embodiments 4-6 are all disposed outside the bottom bracket transmission, while the present embodiment is disposed inside the first planet carrier 20, so that the structure of the central motor can be more compact.

As shown in the figure, the stator 71 of the motor 7 is fixed on a certain part of the frame 6 and is not connected with the central shaft 1, and the rotor 72 is arranged outside the stator 71 and is fixedly connected with the first planet carrier 20, so that an inner stator 71 and outer rotor 72 motor 7 structure is formed, when the motor 7 is electrified, the rotor 72 is driven to rotate at a high speed, and the rotor 72 drives the first planet carrier 20 to output torque, because the torque superposition effect can be achieved.

Example 8

Fig. 22 shows a schematic structural diagram of an embodiment 8 of a central motor in the present application, which is different from embodiment 5 in that the positions of the electronic stator 71 and the rotor 72 are exchanged, specifically, the stator 71 of the motor 7 is fixed on a certain part of the frame 6 and is not connected with the central shaft 1, the rotor 72 is disposed inside the stator 71 and is fixedly connected with the central shaft 1, so as to form a structure of an outer stator 71 and an inner rotor 72 motor 7, when the motor 7 is electrified, the rotor 72 is driven to rotate at a high speed, and the rotor 72 drives the central shaft 1 to output torque, because the effect of torque superposition can be achieved. Because the torque input by the middle shaft 1 and the torque output by the motor 7 both act on the middle shaft 1 and share the same transmission mechanism 2, the motor 7 does not need to be additionally provided with a second reduction mechanism 8, so that the volume of the whole device is further reduced.

Example 9

Fig. 23 shows a schematic structural view of the present bottom bracket transmission embodiment 9, fig. 25 shows a perspective view of the present bottom bracket transmission embodiment 9, fig. 26 shows a front view of the present bottom bracket transmission embodiment 9, and fig. 27 shows a longitudinal sectional view of the present bottom bracket transmission embodiment 9. The difference from embodiment 3 is that the installation position of the planetary gear mechanism is adjusted. In embodiment 3, the first group of planetary gear mechanisms 21 and the second group of planetary gear mechanisms 22 are both sun gear input torques, the carrier output torques are reduction gears, the third group of planetary gear mechanisms 23, the fourth group of planetary gear mechanisms 24, the fifth group of planetary gear mechanisms 25 and the sixth group of planetary gear mechanisms 26 are all carrier input torques, and the sun gear output torques are acceleration gears. According to the power calculation formula, under the condition of the same power, the lower the rotating speed is, the larger the torque is, the torque borne by each part in the first group of planetary gear mechanisms 21 and the second group of planetary gear mechanisms 22 is increased, the torque exceeds the torque input by the central shaft 1, and in order to ensure the service life, the wall thickness of the sun gear, the planetary gear and the gear ring is increased, so that the volume and the weight of the whole central shaft transmission are increased.

After the setting position of the planetary gear mechanism is adjusted, the planetary gear mechanism of the speed increasing transmission is arranged at the torque input end, and the planetary gear mechanism of the speed reducing transmission is arranged at the torque output end, so that the torque after passing through the planetary gear mechanism of the speed increasing transmission can be reduced, the wall thickness of each part of the planetary gear mechanism of the speed increasing transmission can be properly reduced, and the purposes of reducing the volume and the weight of the centrally arranged transmission are achieved.

In the present embodiment, a seventh group planetary gear mechanism 27, an eighth group planetary gear mechanism 28, a ninth group planetary gear mechanism 29, a tenth group planetary gear mechanism 2100, an eleventh group planetary gear mechanism 2110, a twelfth group planetary gear mechanism 2120 are provided, wherein the seventh group planetary gear mechanism 27, the eighth group planetary gear mechanism 28, the ninth group planetary gear mechanism 29, and the tenth group planetary gear mechanism 2100 are speed-increasing gears, and the eleventh group planetary gear mechanism 2110 and the twelfth group planetary gear mechanism 2120 are speed-reducing gears.

a seventh group of planetary gear mechanisms 27 including a seventh planetary gear 272 and a seventh ring gear 273, the seventh ring gear 273 being internally meshed with the seventh planetary gear 272;

An eighth group of planetary gear mechanisms 28 including an eighth sun gear 281, an eighth planetary gear 282, and an eighth ring gear 283, the eighth planetary gear 282 being in external engagement with the eighth sun gear 281, the eighth ring gear 283 being in internal engagement with the eighth planetary gear 282;

the ninth group of planetary gear mechanisms 29 includes a ninth sun gear 291, a ninth planetary gear 292, and a ninth ring gear 293, the ninth planetary gear 292 being in external engagement with the ninth sun gear 291, the ninth ring gear 293 being in internal engagement with the ninth planetary gear 292;

a tenth set of planetary gear mechanisms 2100, comprising a tenth planetary gear 21002 and a tenth ring gear 21003, the tenth ring gear 21003 being in internal mesh with the tenth planetary gear 21002;

an eleventh group planetary gear mechanism 2110 including an eleventh planetary gear 21102 and an eleventh ring gear 21103, the eleventh ring gear 21103 being in internal mesh with the eleventh planetary gear 21102;

a twelfth set of planetary gear mechanisms 2120 including a twelfth sun gear 21201, twelfth planetary gears 21202, and a twelfth ring gear 21203, the twelfth planetary gears 21202 being in external mesh with the twelfth sun gear 21201, the twelfth ring gear 21203 being in internal mesh with the twelfth planetary gears 21202;

the seventh planetary gear 272, the eighth planetary gear 282, the ninth planetary gear 292 and the tenth planetary gear 21002 are hinged on the first planetary carrier 20, the ninth planetary gear 292 and the tenth planetary gear 21002 are hinged on the second planetary carrier 200, the seventh planetary gear 272 and the eighth planetary gear 282 form a double-joint planetary gear, the ninth planetary gear 292 and the tenth planetary gear 21002 form a double-joint planetary gear, and the eleventh planetary gear 21102 and the twelfth planetary gear 21202 form a double-joint planetary gear;

The eighth sun gear 281, the ninth sun gear 291 and the twelfth sun gear 21201 are combined into a triple sun gear, and the triple sun gear is integrally sleeved on the middle shaft 1 in a cylindrical shape and can rotate relative to the middle shaft 1;

one end of the second carrier 200 is fixedly connected with the sprocket 5.

One end of the fixing mechanism 3 is connected to the frame 6, the other end is connected to the gear ring, specifically, the fixing mechanism 3 includes a first fixing mechanism 31, a second fixing mechanism 32, a third fixing mechanism 33 and a fourth fixing mechanism 34, one end of the first fixing mechanism 31 is connected to the frame 6, the other end is connected to the eighth gear ring 283, one end of the second fixing mechanism 32 is connected to the frame 6, the other end is connected to the ninth gear ring 293, one end of the third fixing mechanism 33 is connected to the frame 6, the other end is connected to the tenth gear ring 21003, one end of the fourth fixing mechanism 34 is connected to the frame 6, and the other end is connected to the eleventh gear ring 21103. One end of the one-way clutch assembly 4 is connected to the frame 6, the other end is connected to another part of the gear ring, the one-way clutch assembly 4 specifically comprises a first one-way clutch assembly 41 and a second one-way clutch assembly 42, one end of the first one-way clutch assembly 41 is connected to the frame 6, the other end is connected to the seventh gear ring 273, one end of the second one-way clutch assembly 42 is connected to the frame 6, and the other end is connected to the twelfth gear ring 21203.

Fig. 24 is a power transmission path diagram of a certain gear of the axial transmission embodiment 9 of the present application.

As shown in the drawing, at this time, the first fixing mechanism 31 and the fourth fixing mechanism 34 are in the operating state, the first one-way clutch assembly 41 and the second one-way clutch assembly 42 are in the separated state, and the torque generated by the stepping of the rider is input from the center shaft 1, and the seventh ring gear 273, the ninth ring gear 293, the tenth ring gear 21003, and the twelfth ring gear 21203 are not fixed, so that the seventh ring gear 273, the ninth ring gear 293, the tenth ring gear 21003, and the twelfth ring gear 21203 are in the idling state, and do not output torque, which corresponds to the failure of the seventh group planetary gear mechanism 27, the ninth group planetary gear mechanism 29, the tenth group planetary gear mechanism 2100, and the twelfth group planetary gear mechanism 2120, according to the transmission characteristics of the planetary gears. The movement states of the eighth group planetary gear mechanism 28 at this time are: the first planet carrier 20 is active, the eighth ring gear 283 is fixed, the eighth sun gear 281 is active, and in this case, for speed increasing transmission, the movement states of the eleventh group of planetary gear mechanisms 2110 are: the twelfth sun gear 21201 is driving, the eleventh ring gear 21103 is fixed, and the second carrier 200 is driven, which is a reduction gear at this time.

The power transmission path diagrams of the other gears are similar to those shown in fig. 10 to 17 of embodiment 3, and will not be described again here.

Fig. 29 is a perspective view of the fixing mechanism 3 of the present application. Fig. 30 is a front view of the fixing mechanism 3 of the present application.

In this embodiment, the fixing mechanism 3 adopts a ratchet pawl mechanism, and compared with a brake mechanism, the ratchet pawl mechanism has the characteristics of simple structure, convenient control, convenient assembly, easy maintenance and the like, because the brake mechanism needs a brake disc, a hydraulic cylinder and a brake caliper, the hydraulic cylinder drives the brake caliper to clamp the brake disc to achieve fixing, however, the hydraulic cylinder needs hydraulic oil as a medium for pushing the brake caliper to move, so that the fixing mechanism 3 is too large in volume, and the hydraulic oil needs severe sealing conditions, otherwise, the fixing mechanism 3 is easy to fail due to leakage.

The fixing mechanism 3 comprises a control pawl and a control cam, wherein claw parts are arranged at two ends of the control pawl, the middle of the control pawl is rotatably arranged on a certain pivot, the claw parts at one end of the control pawl are propped against the control cam and are in sliding connection, when the control cam rotates, the control cam drives the control pawl to swing, so that the drive control pawl is locked or unlocked with a ratchet groove arranged on the gear ring, and when the control pawl is engaged with the ratchet groove, the unidirectional rotation of the gear ring is blocked, and the effect of fixing the gear ring is realized.

Since the control pawl needs to resist the acting force of the ratchet groove on the control pawl, the control pawl needs to be effectively fixed, in this embodiment, by arranging the housing 35 outside the transmission mechanism 2, the housing 35 is connected with the frame 6, the outer peripheral surface of the housing 35 is provided with the avoiding grooves 351 which can enable the control pawl to contact with the ratchet groove, and since the control pawl is provided with four, the control pawl 311, the second control pawl 321, the third control pawl 331 and the fourth control pawl 341 are respectively provided with four avoiding grooves 351 correspondingly. The casing 35 is cylindrical, the inner diameter of the casing 35 is slightly larger than the outer diameter of the gear ring of the transmission mechanism 2, a rotating shaft 352 is fixedly arranged on the outer side of the casing 35, and the rotating shaft 352 sequentially penetrates through the four control pawls and is hinged with the four control pawls respectively, so that the control pawls swing around the axis of the rotating shaft 352 serving as a fulcrum.

In order to regularly control the gear ring to be fixed, a first control cam 312, a second control cam 322, a third control cam 332 and a fourth control cam 342 are respectively arranged to correspondingly control the control pawls, and the four control cams are arranged on the same cam shaft 36, so that synchronous rotation of the four control cams can be ensured to ensure accurate gear shifting of the bottom bracket transmission. While eighth ratchet grooves 2831, ninth ratchet grooves 2931, tenth ratchet grooves 210031, eleventh ratchet grooves 211031 are provided on the eighth gear ring 283, the ninth gear ring 293, the tenth gear ring 21003, and the eleventh gear ring 21103, respectively, the control cam rotates to engage or disengage the control pawl with the ratchet grooves.

As shown in fig. 31, the outer peripheral surface of the first control cam 312 always abuts against one end of the first control pawl 311, and during the rotation of the first control cam 312, one end of the first control pawl 311 slides against the outer peripheral surface of the first control cam 312, at this time, the first control pawl 311 does not contact the eighth ratchet groove 2831, the eighth ring gear 283 normally rotates, the first control groove 3121 is provided on the outer peripheral surface of the first control cam 312, and when one end of the first control pawl 311 slides into the first control groove 3121, the first control pawl 311 swings, and when the pawl portion of the first control pawl 311 adjacent to the eighth ring gear 283 is engaged with the eighth ratchet groove 2831, the eighth ring gear 283 is prevented from unidirectional rotation.

The torsion spring may be provided on the rotation shaft 352, one end of the torsion spring being connected to one end of the control pawl, the other end of the torsion spring being connected to the housing 35, the torsion spring applying a force toward the ratchet groove to the control pawl while the control pawl abuts against the outer peripheral surface of the control cam.

Similarly, the second control cam 322, the third control cam 332, and the fourth control cam 342 are provided with the second control groove 3221, the third control groove 3321, and the fourth control groove 3421, respectively, and since the seventh group of planetary gear mechanisms 27, the eighth group of planetary gear mechanisms 28, the ninth group of planetary gear mechanisms 29, and the tenth group of planetary gear mechanisms 2100 share the same first carrier 20, if more than two ring gears are simultaneously fixed, the ring gears can be locked, and therefore, only one ring gear can be fixed, and thus, the opening angles of the first control groove 3121, the second control groove 3221, and the third control groove 3321 are different, so that only one control pawl is locked into the control groove when the rotation to a certain specific gear angle can be ensured.

Since the eleventh group of planetary gear mechanisms 2110 and the twelfth group of planetary gear mechanisms 2120 share the second carrier 200, the groove type of the fourth control groove 3421 depends on the actual gear shift.

The control pawl rotates around the axis of the rotating shaft 352, the shaft center of the rotating shaft 352 is used as a fulcrum to form a lever, and the lever can be formed into a labor-saving lever or a labor-saving lever by adjusting the distance from the contact point of the control pawl and the control cam to the fulcrum and the distance from the contact point of the control pawl and the ratchet groove to the fulcrum.

If the distance from the contact point of the control pawl and the control cam to the fulcrum is greater than the distance from the contact point of the control pawl and the ratchet groove to the fulcrum, a labor-saving lever is formed, and because the control pawl is clamped into the ratchet groove and generates a larger acting force, the driving device 371 can generate a larger output force with a smaller force in the rotation process, so that the control pawl can be more easily separated from the ratchet groove, and the device is suitable for a fixing mechanism 3 which can generate a larger acting force, such as an eighth group of planetary gear mechanism 28, a ninth group of planetary gear mechanism 29 and a tenth group of planetary gear mechanism 2100 of a reduction transmission.

If the distance from the contact point of the control pawl and the control cam to the fulcrum is smaller than the distance from the contact point of the control pawl and the ratchet groove to the fulcrum, a laborious lever is formed, and then the driving device 371 swings at a larger displacement and a quicker shifting speed under the same rotation angle in the rotation process, so that the device is suitable for the fixing mechanism 3 which does not generate a larger acting force, such as an eleventh group of planetary gear mechanism 2110 of speed-increasing transmission.

In order to drive the camshaft 36 to rotate, in this embodiment, an electric gear shifting mechanism 37 is used for driving, the electric gear shifting mechanism 37 includes a driving device 371, the driving device 371 is an encoder motor 7, the encoder motor 7 can acquire information such as a position, a speed, an angle and the like of the motor 7 motion in real time through the encoder, and the encoder motor has high measurement precision and accuracy, and is suitable for application scenes with high requirements on precision such as the position, the speed, the angle and the like.

The output end of the driving device 371 is connected with a first speed reducing mechanism 372, the first speed reducing mechanism 372 can be a multi-stage gear reducer, the torque of the driving device 371 is increased through the first speed reducing mechanism 372, a buffer device 373 is further arranged at the end part of the cam shaft 36, if clamping stagnation occurs in the cam shaft 36 in the gear shifting process, the buffer device 373 can absorb the torque generated by the driving device 371, the buffer effect is achieved, the damage to parts is avoided, the driving device 371 is not burnt down, and the service life of the driving mechanism is effectively prolonged.

In order to acquire gear information of the centrally-mounted transmission in real time, a gear feedback device 374 is further provided at an end of the camshaft 36, the gear feedback device 374. The shift feedback device 374 includes a magnet, a circuit board, and a plurality of hall elements disposed on the circuit board. In this embodiment, the centrally-mounted transmission is provided with eight gears, so that the hall elements are provided with eight corresponding, and the magnets are mounted on the swing arms fixed to the cam shaft 36, and when the driving device 371 drives the cam shaft 36 to rotate, the magnets on the swing arms sweep over the hall elements, and the hall elements induce a change in magnetic field intensity to generate a corresponding pulse, so that it is possible to determine which gear to rotate by acquiring the pulse signal.

In addition, the vehicle to which the center transmission is applied is also provided with a speed feedback device that acquires positioning information, for example, by adding a GPS chip and acquires the speed of the vehicle by calculation, and in the automatic mode, the center transmission performs a shift operation according to the speed of the vehicle without any operation by the rider, for example, automatically upshifting from first gear to second gear when the speed of the vehicle reaches ten km/hour; for another example, when the vehicle speed decreases below ten kilometers per hour, the vehicle is automatically shifted from second gear to first gear. The rider can freely change the gear according to the actual road condition by switching to the manual mode, so that the riding flexibility is improved, and the riding comfort is improved by switching to the free mode to automatically change the gear.

Or a built-in pedal frequency sensor and a torque sensor of the middle transmission are arranged, the pedal moment of a rider and the pedal frequency speed are obtained, the rider is comprehensively judged to be in an ascending state, a flat land rapid acceleration and deceleration state, a flat land slow acceleration and deceleration state and a descending state according to an internal algorithm, and the driving device 371 is automatically controlled to shift gears, so that the automatic gear shifting effect is realized.

Fig. 32 is a perspective view of the embodiment 10 of the bottom bracket derailleur (manual shift mechanism 38) of the present application, and fig. 33 is a perspective view of the embodiment 10 of the bottom bracket derailleur (manual shift mechanism 38, hidden fixed disk 381) of the present application.

In this embodiment, the camshaft 36 is driven by a manual gear shifting mechanism 38, the manual gear shifting mechanism 38 includes a fixed disc 381, a rotating disc 383, a control line 384 and a gear shifter for driving the control line 384 to move, a through hole is provided in the middle of the fixed disc 381, the rotating disc 383 is sleeved inside the fixed disc 381 and can rotate relative to the fixed disc 381, the fixed disc 381 can be fixed at any non-moving part of the centrally installed transmission or the frame 6, a slot is provided above the fixed disc 381, a spool 382 is fixedly mounted in the slot, the arrangement position of the spool 382 is set along the tangential direction of the rotating disc 383, and the control line 384 passes through the spool 382 from top to bottom and is connected with the rotating disc 383.

In order to allow the control wire 384 to drive the cam shaft 36 to rotate, a spiral wire groove 383 is provided on the outer circumferential surface of the rotating disk 383, and the control wire 384 is wound around the wire groove 383 along the wire groove 3831, and one end is fixed to one portion of the rotating disk 383. When the control line 384 is pulled upward by the shifter, the control line 384 will rotate the rotating disk 383, thereby rotating the cam shaft 36 fixed to the rotating disk 383, and when the control line 384 is released by the shifter, the rotating disk 383 rotates reversely under the action of the elastic reset member, thereby rotating the cam shaft 36 fixed to the rotating disk 383 reversely.

The control wire 384 is typically a wire such as a steel wire that is not easily deformed.

Compared with the electric gear shifting mechanism 37, the manual gear shifting mechanism 38 has fewer parts, simple structure, no need of electric drive, no complicated electronic components and electric system, and high reliability, but the control line 384 is rusted and lengthened after long-time use, so that the control line 384 cannot pull or release the cam shaft 36 according to the same distance, and further the gear shifting is difficult, jerky or impossible.

Example 10

Fig. 34 is a schematic structural view of an embodiment 10 of the center motor 7 of the present application, fig. 35 is one of perspective views of an embodiment 10 of the center motor 7 of the present application, fig. 36 is the second perspective view of an embodiment 10 of the center motor 7 of the present application, fig. 37 is the third perspective view of an embodiment 10 of the center motor 7 of the present application, and fig. 38 is the fourth perspective view of an embodiment 10 of the center motor 7 of the present application.

In this embodiment, the output end of the motor 7 is provided with the second speed reducing mechanism 8, the second speed reducing mechanism 8 includes a first speed reducing gear 81, a second speed reducing gear 82 and a third speed reducing gear 83, the first speed reducing gear 81 is mounted on the output shaft of the motor 7, the third speed reducing gear 83 is mounted on the second planet carrier 200 of the transmission mechanism 2, the second speed reducing gear 82 is mounted between the first speed reducing gear 81 and the third speed reducing gear 83, the number of teeth of the first speed reducing gear 81, the second speed reducing gear 82 and the third speed reducing gear 83 is sequentially increased, the second speed reducing mechanism 8 forms two-stage speed reduction, the rotating speed of the motor 7 is reduced to improve the torque of the motor 7, the torque generated by stepping on the pedal is added with the torque generated by the motor 7, and finally the torque is output to the sprocket 5.

The outside of putting motor 7 is provided with protective housing 10, and protective housing 10 protects all electronic component and mechanical element including, prevents to receive the harm of external factors such as collision, scraping, water and dust, and part of protective housing 10 adopts the metal material, can play the effect of cooling motor 7, and the heat transfer outside inside motor 7 through the mode of heat conduction guarantees to put motor 7 normal operating.

The fixed end of the fixing mechanism 3 is connected with the protective shell 10, and then the protective shell 10 is connected with the frame 6, so that the aim of indirectly connecting the fixing mechanism 3 with the frame 6 is fulfilled.

In the description of the present specification, reference to the terms "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

What has been described above is merely some embodiments of the present invention. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit of the invention.

Claims

1. A bottom bracket transmission, comprising:

a center shaft (1), wherein the center shaft (1) is rotatably supported on a frame (6), and torque is input from the center shaft (1);

the transmission mechanism (2) is connected with the middle shaft (1), and the transmission mechanism (2) has at least one transmission ratio;

a fixing mechanism (3), one end of which is connected with the frame (6) and the other end of which is connected with a part of the transmission mechanism (2);

one end of the one-way clutch component (4) is connected with the frame (6), and the other end is connected with the other part of the transmission mechanism (2);

a sprocket (5) fixed on the transmission mechanism (2) for outputting torque;

after the torque passes through the transmission mechanism (2), parts of a part of the transmission mechanism (2) and the frame (6) are relatively fixed by controlling the fixing mechanism (3) so as to change the transmission ratio.

2. The bottom bracket transmission according to claim 1, characterized in that the transmission mechanism (2) is a plurality of sets of planetary gear mechanisms.

3. The bottom bracket transmission according to claim 2, characterized in that one end of the fixing mechanism (3) is connected to the frame (6) and the other end is connected to a gear ring of a part of the transmission mechanism (2).

4. The bottom bracket transmission according to claim 2, characterized in that one end of the one-way clutch assembly (4) is connected to the frame (6) and the other end is connected to the ring gear of the other part of the transmission mechanism (2).

5. The bottom bracket transmission according to claim 2, wherein the transmission mechanism (2) is at least one of a reduction transmission and a speed increasing transmission.

6. The bottom bracket transmission according to claim 2, wherein the transmission mechanism (2) is a compound transmission which is subjected to speed increasing transmission and then to speed reducing transmission.

7. The bottom bracket transmission according to claim 6, wherein the transmission mechanism (2) comprises:

a seventh group of planetary gear mechanisms (27) including a seventh planetary gear (272) and a seventh ring gear (273), the seventh ring gear (273) being internally meshed with the seventh planetary gear (272);

an eighth group of planetary gear mechanisms (28) including an eighth sun gear (281), an eighth planetary gear (282), and an eighth ring gear (283), the eighth planetary gear (282) being in external engagement with the eighth sun gear (281), the eighth ring gear (283) being in internal engagement with the eighth planetary gear (282);

a ninth group of planetary gear mechanisms (29) including a ninth sun gear (291), a ninth planetary gear (292), and a ninth ring gear (293), the ninth planetary gear (292) being in external engagement with the ninth sun gear (291), the ninth ring gear (293) being in internal engagement with the ninth planetary gear (292);

A tenth group of planetary gear mechanisms (2100) including a tenth planetary gear (21002) and a tenth ring gear (21003), the tenth ring gear (21003) being in internal mesh with the tenth planetary gear (21002);

an eleventh group planetary gear mechanism (2110) including an eleventh planetary gear (21102) and an eleventh ring gear (21103), the eleventh ring gear (21103) being in internal mesh with the eleventh planetary gear (21102);

a twelfth group of planetary gear mechanisms (2120) including a twelfth sun gear (21201), twelfth planetary gears (21202), and a twelfth ring gear (21203), the twelfth planetary gears (21202) being externally meshed with the twelfth sun gear (21201), the twelfth ring gear (21203) being internally meshed with the twelfth planetary gears (21202);

a seventh planetary gear (272), an eighth planetary gear (282), a ninth planetary gear (292) and a tenth planetary gear (21002) are hinged on the first planetary frame (20), the ninth planetary gear (292) and the tenth planetary gear (21002) are hinged on the second planetary frame (200), the seventh planetary gear (272) and the eighth planetary gear (282) form a double-linked planetary gear, the ninth planetary gear (292) and the tenth planetary gear (21002) form a double-linked planetary gear, and the eleventh planetary gear (21102) and the twelfth planetary gear (21202) form a double-linked planetary gear;

The eighth sun gear (281), the ninth sun gear (291) and the twelfth sun gear (21201) are combined into a triple sun gear, and the triple sun gear is integrally sleeved on the middle shaft (1) in a cylindrical manner and can rotate relative to the middle shaft (1);

one end of the second planet carrier (200) is fixedly connected with the chain wheel (5).

8. The bottom bracket transmission according to claim 7, wherein one end of the fixing mechanism (3) is connected to the frame (6), the other end is connected to the eighth gear ring (283), the ninth gear ring (293), the tenth gear ring (21003) and the eleventh gear ring (21103), respectively, and one end of the one-way clutch assembly (4) is connected to the frame (6), and the other end is connected to the seventh gear ring (273) and the twelfth gear ring (21203), respectively.

9. The bottom bracket transmission according to claim 2, characterized in that the transmission mechanism (2) comprises:

a first group of planetary gear mechanisms (21) comprising a first sun gear (211), a first ring gear (213) and a first planetary gear (212), wherein the first planetary gear (212) is externally meshed with the first sun gear (211), and the first ring gear (213) is internally meshed with the first planetary gear (212);

a second group of planetary gear mechanisms (22) comprising a second sun gear (221), a second ring gear (223) and second planetary gears (222), wherein the second planetary gears (222) are externally meshed with the second sun gear (221), and the second ring gear (223) is internally meshed with the second planetary gears (222);

The first planetary gear (212) and the second planetary gear (222) are hinged on a first planet carrier (20);

the first sun gear (211) and the second sun gear (221) are fixedly connected with the middle shaft (1);

the first planet carrier (20) is rotatably supported on the center shaft (1) and one end of the first planet carrier is fixedly connected with the chain wheel (5).

10. The bottom bracket transmission according to claim 9, wherein one end of the fixing mechanism (3) is connected to the frame (6), the other end is connected to the first gear ring (213), and one end of the one-way clutch assembly (4) is connected to the frame (6), and the other end is connected to the second gear ring (223).

11. The bottom bracket transmission according to claim 5, characterized in that the transmission mechanism (2) comprises:

A third group of planetary gear mechanisms (23) comprising a third ring gear (233) and third planetary gears (232), wherein the third ring gear (233) is internally meshed with the third planetary gears (232);

a fourth set of planetary gear mechanisms (24) including a fourth sun gear (241), a fourth ring gear (243), and fourth planetary gears (242), the fourth planetary gears (242) being in external engagement with the fourth sun gear (241), the fourth ring gear (243) being in internal engagement with the fourth planetary gears (242);

the first planetary gear (212), the second planetary gear (222), the third planetary gear (232) and the fourth planetary gear (242) are hinged on the first planetary carrier (20), and the third planetary gear (232) and the fourth planetary gear (242) are combined into a first duplex planetary gear;

the fourth sun gear (241) is rotatably supported on the center shaft (1) and one end of the fourth sun gear is fixedly connected with the sprocket (5).

12. The bottom bracket transmission according to claim 11, wherein one end of the fixing mechanism (3) is connected to the frame (6), the other end is connected to the first gear ring (213) and the fourth gear ring (243), respectively, one end of the one-way clutch assembly (4) is connected to the frame (6), and the other end is connected to the second gear ring (223) and the third gear ring (233), respectively.

13. The bottom bracket transmission according to claim 11, wherein the transmission mechanism (2) further comprises:

a fifth group of planetary gear mechanisms (25) including a fifth sun gear (251), a fifth ring gear (253), and a fifth planetary gear (252), the fifth planetary gear (252) being externally meshed with the fifth sun gear (251), the fifth ring gear (253) being internally meshed with the fifth planetary gear (252);

a sixth group of planetary gear mechanisms (26) including a sixth ring gear (263), a sixth planetary gear (262), the sixth ring gear (263) being in internal mesh with the sixth planetary gear (262);

the first planetary gear (212), the second planetary gear (222), the third planetary gear (232), the fourth planetary gear (242), the fifth planetary gear (252) and the sixth planetary gear (262) are hinged on a first planet carrier (20), the third planetary gear (232) and the fourth planetary gear (242) are combined to form a first duplex planetary gear, and the fifth planetary gear (252) and the sixth planetary gear (262) are combined to form a second duplex planetary gear;

-the fourth sun gear (241) and the fifth sun gear (251) are combined into a double sun gear;

the fourth sun gear (241) and the fifth sun gear (251) are rotatably supported on the center shaft (1) and one end is fixedly connected with the sprocket (5).

14. The bottom bracket transmission according to claim 13, wherein one end of the fixing mechanism (3) is connected to the frame (6), the other end is connected to the first gear ring (213), the fourth gear ring (243), the fifth gear ring (253) and the sixth gear ring (263), respectively, one end of the one-way clutch assembly (4) is connected to the frame (6), and the other end is connected to the second gear ring (223) and the third gear ring (233), respectively.

15. A mid-motor comprising a bottom bracket transmission according to any one of claims 1-14, further comprising a motor (7), said motor (7) being connected to said bottom bracket (1) or to said transmission (2).

16. A mid-motor according to claim 15, characterized in that the motor (7) is arranged coaxially with the central shaft (1).

17. A mid-motor according to claim 15, characterized in that the motor (7) and the central shaft (1) are arranged with their axes parallel to each other.

18. A mid-motor according to claim 15, characterized in that the motor (7) is arranged with the axis of the central shaft (1) perpendicular to each other.

19. The mid-motor according to any one of claims 15-18, characterized in that the motor (7) is connected to the central shaft (1) or the transmission mechanism (2) by any one of chain transmission, belt transmission, gear transmission.