CN117006212A

CN117006212A - Resistance transmission mechanism

Info

Publication number: CN117006212A
Application number: CN202210461413.4A
Authority: CN
Inventors: 请求不公布姓名
Original assignee: Beijing Mitao Zhilian Technology Co ltd
Current assignee: Beijing Mitao Zhilian Technology Co ltd
Priority date: 2022-04-28
Filing date: 2022-04-28
Publication date: 2023-11-07

Abstract

The present invention provides a resistance transmission mechanism for exercise equipment, comprising: the resistance source with the input shaft, two-stage planetary transmission group, first wire reel and second wire reel, wherein, two-stage planetary transmission group includes the sun gear, has planetary gear group, planet carrier and the external gear of first planet wheel, second planet wheel and planetary axle, the sun gear be fixed in the input shaft and with first planet wheel intermeshing, the external gear rotationally cup joint in the input shaft and with second planet wheel intermeshing, first planet wheel with the second planet wheel has different diameters, all is fixed in on the planetary axle and rotationally set up in the planet carrier, first wire reel set up in the planet carrier, the second wire reel set up in the external gear.

Description

Resistance transmission mechanism

Technical Field

The invention belongs to the technical field of body-building equipment, and particularly relates to a resistance transmission mechanism for body-building equipment.

Background

Along with the improvement of the living standard of people and the popularization of the body-building equipment for the whole people, more and more people utilize the body-building equipment to exercise the body. The body-building equipment in the market has various varieties and various functions. Novel intelligent electric resistance training apparatus is gradually entering the market. Through running block structure and motor matched with in order to provide the resistance, utilize running block to distribute the resistance from a stay cord to two stay cords, this structure needs great space in order to be used for the motion of running block, consequently this mode needs to occupy great space, is difficult for installing in body-building equipment, and hardly realizes great reduction ratio and enlarges the pulling force of motor.

U.S. patent No. 10617903B2 discloses a differential mechanism of exercise equipment, which is provided with two winding assemblies with the same diameter and can output torque simultaneously, but the differential mechanism is formed by adopting bevel gears, chain wheels and other parts, the bevel gears are difficult to process, the noise is larger, synchronous belt transmission is required for the structure, the parts are more, the structure is more complex, the cost is quite high, and the large reduction ratio is difficult to realize.

In addition, there is also a body-building apparatus using an inner gear ring in the differential mechanism, but when manufacturing the inner gear ring, a broaching machine, a gear turning machine and a gear shaping machine are generally used for production, so that the production process is complicated, and the processing difficulty is high. In addition, for the differential mechanism adopting the annular gear, the machining precision is difficult to control, so that deviation exists in the matching among all components, the engagement between all components and the annular gear sometimes occurs to be blocked, perfect engagement cannot be realized, the friction is increased, the running of the equipment is not smooth, the noise is increased, and the noise is difficult to control. In addition, if the machining hardness and machining accuracy of the tooth surface of the ring gear have to be improved in order to control noise, the machining difficulty is further increased in the originally troublesome machining process, and the manufacturing cost is also difficult to control. In addition, the inertia of the inner gear ring is very large, and the inner gear ring is sensitive to the inertia in the application field of body-building equipment. If the inertia is too great, the rope movement state change (acceleration, deceleration, reverse) becomes sluggish, so that when the exerciser uses the exercise apparatus using the internal gear, the experience feeling thereof is deteriorated.

Patent document 1

U.S. Pat. No. 3,182,62B 2

Disclosure of Invention

Problems to be solved by the invention

The invention provides a resistance transmission mechanism for body-building equipment, which aims to solve the problems that an existing resistance transmission mechanism needs to occupy a large space, has large noise, small speed reduction, large inertia, high cost and the like, and solves the technical defect of the existing resistance transmission mechanism.

Technical scheme for solving problems

The invention relates to a resistance transmission mechanism, which is used for body-building equipment and is characterized by comprising the following components: the resistance source with the input shaft, two-stage planetary transmission group, first wire reel and second wire reel, wherein, two-stage planetary transmission group includes the sun gear, has planetary gear group, planet carrier and the external gear of first planet wheel, second planet wheel and planetary axle, the sun gear be fixed in the input shaft and with first planet wheel intermeshing, the external gear rotationally cup joint in the input shaft and with second planet wheel intermeshing, first planet wheel with the second planet wheel has different diameters, all is fixed in on the planetary axle and rotationally set up in the planet carrier, first wire reel set up in the planet carrier, the second wire reel set up in the external gear.

Preferably, the sun gear, the first planetary gear, the second planetary gear and the external gear are all cylindrical gears.

Preferably, the resistance transmission mechanism further comprises a first pull wire and a second pull wire, wherein the first pull wire is wound on the first wire spool, and the second pull wire is wound on the second wire spool.

Preferably, one of the first planetary gear and the second planetary gear has a sleeve and is mounted on the planetary gear shaft via two planetary gear bearings, the other of the first planetary gear and the second planetary gear is mounted on the sleeve through a joint, and the planetary gear shaft is inserted into a mounting hole of the planet carrier.

Preferably, the first planet and the second planet are mounted via a planet bearing on a planet axle, the planet axle being arranged in a mounting hole of the planet carrier.

Preferably, the resistance transmission mechanism further includes a second bearing which is coupled to a radially outer side of one end of the input shaft and is engaged with a radially inner side of the external gear, and the external gear is mounted to the input shaft via the second bearing.

Preferably, the resistance transmission mechanism further includes a first bearing sleeved on a radially outer side of the external gear and a third bearing sleeved on a radially outer side of the other end of the input shaft, and the planet carrier is mounted on the planetary gear set via the first bearing and the third bearing.

Preferably, the number of the second bearings is two, and the number of the first bearings and the number of the third bearings are one respectively.

Preferably, the planetary gear bearing is a needle roller bearing, and the planetary gear shaft is a needle roller shaft.

Effects of the invention

(1) According to the resistance transmission mechanism, the requirement of double-rope output which can be realized by two motors can be realized by matching one motor with one secondary transmission group, so that the cost is greatly reduced, and compared with the scheme that the two motor output shafts directly wind a pull rope, the resistance transmission mechanism provided by the invention has larger output tension and torque. In addition, not only the number of motors can be reduced, but also the cost of the drivers and the gears and the accessory structures required by the motors can be reduced.

(2) In addition, when manufacturing the ring gear, the manufacturing cost of the single ring gear is generally 10 times or more the manufacturing cost of the single outer ring gear of the same specification. In the invention, the differential mechanism is skillfully designed, and only the outer ring gear is used instead of the structure with the inner ring gear by utilizing the mutual matching between the two-stage transmission group and each gear, so that the use cost can be better reduced. Moreover, the process of manufacturing the outer ring gear member is far simpler than the process of manufacturing the inner ring gear member, so that the manufacturing process can be simplified by the present invention, and complicated ring gear processing can be omitted, thereby further reducing the manufacturing cost. That is, the invention has lower manufacturing precision requirement, fewer parts, lower cost and lower noise

(3) In addition, compared with the differential structure scheme of the movable pulley rope, the resistance transmission mechanism provided by the invention has no risk of pulley rope falling, has higher reliability, and can more conveniently realize the requirements of speed reduction and torque increase.

(4) In addition, the invention adopts the cylindrical gears, compared with the bevel gear differential structure, the structure of the invention is simpler and more compact, synchronous belts and synchronous wheel transmission are not needed, the processing cost of the cylindrical gears is far lower than that of other types of gears such as sector gears and the like, and the easiness of realizing the same processing precision is far lower than that of other gears, so that the higher precision can be realized with lower cost, the cost can be reduced, and the high precision can be realized more easily, and the low noise can be realized more easily.

(5) In addition, compared with a movable pulley rope differential structure, a bevel gear differential structure and a double-motor scheme, the resistance transmission mechanism provided by the invention only occupies a small space, and can realize the resistance transmission requirement of single motor double-wire, so that the installation place is not limited to gymnasiums, and the resistance transmission mechanism can be installed in more places such as houses, offices and leisure places.

Drawings

FIG. 1 is a cross-sectional view of a drag drive mechanism of one embodiment of the present invention;

FIG. 2 is an assembled schematic view of a resistance drive mechanism according to one embodiment of the present invention.

Description of the reference numerals

1: input shaft of resistance source

2: two-stage planetary transmission set

21: sun gear

22: planetary gear set

22a: big planet wheel (first planet wheel)

22b: small planet wheel (second planet wheel)

22c: needle roller (Planet wheel axle)

22d: needle roller bearing (Planet wheel bearing)

22e: needle roller bearing (Planet wheel bearing)

23: planet carrier

24: external gear

3: first wire spool

31: first stay wire

4: second wire spool

41: second stay wire

51: first bearing

52a, 52b: second bearing

53: third bearing

Detailed Description

The present invention will be described in detail with reference to the accompanying drawings.

Fig. 1 shows a cross-sectional view of a drag drive mechanism of one embodiment of the present invention, and fig. 2 shows an assembled schematic view of a drag drive mechanism of one embodiment of the present invention. As shown in fig. 1 and 2, the resistance transmission mechanism of the present embodiment includes: a resistance source with an input shaft 1, a two-stage planetary gear set 2, a first spool 3 and a second spool 4. The two-stage planetary gear set 2 includes a sun gear 21, a planetary gear set 22, a planet carrier 23, and an external gear 24. In the present embodiment, the motor is described as an example of the resistance source, but the present invention is not limited to this, and one or more of wind resistance, magnetic resistance, and water resistance may be used.

Referring to fig. 1 and 2, the planetary gear set 22 of the present invention includes a large planetary gear 22a and a small planetary gear 22b, wherein the large planetary gear 22a and the small planetary gear 22b are fixed together with a prescribed interval therebetween by, for example, a bushing, and are provided on the same shaft (for example, a needle shaft 22c as a planetary gear shaft in the drawing) and are rotatable about the same shaft at the same time. Specifically, as shown in fig. 1 and 2, a needle bearing 22e and a needle bearing 22d are engaged with the inner side of the small planetary gear 22b in the radial direction, wherein a gear portion of the small planetary gear 22b is provided near the outer periphery of the needle bearing 22e, and the outer periphery of the small planetary gear 22b near the needle bearing 22d is formed as a boss, for example, and the small planetary gear 22b can be provided on the needle shaft 22c and the small planetary gear 22b can be pivoted about the needle shaft 22c by coupling the needle bearing 22e and the needle bearing 22d to the needle shaft 22 c. Further, as shown in fig. 1, a joint (for example, a radially outward engaging projection) is provided in the boss portion of the small planetary gear 22b near the outer periphery of the needle bearing 22d, and the large planetary gear 22a is fixed to the boss portion of the small planetary gear 22b near the outer periphery of the needle bearing 22d by the joint, so that the large planetary gear 22a and the small planetary gear 22b are fixed together with a predetermined interval therebetween, are provided on the needle shaft 22c, and are rotatable about the needle shaft 22 c.

The manner of providing the boss in the part of the small planetary gear 22b and fixing the large planetary gear 22a to the boss as described above with respect to the fixation between the large planetary gear 22a and the small planetary gear 22b and the arrangement with respect to the planetary gear shaft are merely examples, and other manners are also possible. For example, a sleeve may be formed on the outer periphery of the large planetary gear 22a near the needle bearing 22e, for example, a gear portion of the large planetary gear 22a may be provided near the outer periphery of the needle bearing 22d, a joint may be provided on the sleeve portion of the large planetary gear 22a near the outer periphery of the needle bearing 22e, and the small planetary gear 22b may be fixed to the sleeve portion of the large planetary gear 22a near the outer periphery of the needle bearing 22e via the joint, so that the large planetary gear 22a and the small planetary gear 22b are fixed together with a predetermined interval therebetween and provided on the needle shaft 22c so as to be rotatable about the needle shaft 22 c.

In the above embodiment, two needle bearings are used, but only one needle bearing may be used. For example, a needle bearing is engaged with the radial inner side of the large planetary gear 22a, and the large planetary gear 22a can be provided on the needle shaft 22c by engaging the needle bearing with the needle shaft 22c, so that the large planetary gear 22a can rotate around the needle shaft 22 c. Similarly, the inner side in the radial direction of the small planetary gear 22b is also engaged with the needle bearing, so that the small planetary gear 22b can be similarly provided on the needle shaft 22c, and the small planetary gear 22b can be similarly pivoted about the needle shaft 22c, and the large planetary gear 22a and the small planetary gear 22b are fixed together at this time. By adopting such a structure, only one needle bearing needs to be provided.

Various means may be employed for the fixation between the large planetary gear 22a and the small planetary gear 22b and the arrangement with respect to the planetary gear shaft, as long as the large planetary gear 22a and the small planetary gear 22b can be fixed together while rotating around the planetary gear shaft. In addition, a combination of needle bearings and needle shafts is used herein, and other means may be used.

As shown in fig. 1 and 2, the planetary gear set 22 can be provided on the carrier 23 by further inserting the needle shaft 22c into the mounting hole provided on the carrier 23, so that the entire planetary gear set 22 can rotate in the rotation direction of the needle shaft 22 c. That is, the large planetary gear 22a and the small planetary gear 22b are coaxially fixed together, and the large planetary gear 22a and the small planetary gear 22b can rotate as a whole about the needle shaft 22 c. The carrier 23 is rotatable in the rotation direction of the input shaft 1 (that is, rotates around the input shaft 1, which will be described later in detail), and therefore the entire planetary gear set 22 can also revolve in the rotation direction of the input shaft 1 around the input shaft 1 in accordance with the rotation of the carrier 23.

In the two-stage planetary gear set 2 of the present embodiment, the large planetary gear 22a and the small planetary gear 22b of the planetary gear set 22 are cylindrical gears.

Further, referring to fig. 1 and 2, in the present embodiment, two second bearings 52a, 52b are sleeved on the radially outer side of one end (lower end in fig. 2) of the input shaft 1 of the motor (resistance source), and the two second bearings 52a, 52b are engaged with the radially inner side of the external gear 24 so that the external gear 24 can rotate in the rotational direction of the input shaft 1.

In addition, referring to fig. 1 and 2, a first bearing 51 is coupled to the radially outer side of the external gear 24, and a third bearing 53 is coupled to the radially outer side of the other end (upper end in fig. 1) of the input shaft 1, and both the first bearing 51 and the third bearing 53 are engaged to the radially inner side of the carrier 23, thereby enabling the carrier 23 to rotate in the rotational direction of the input shaft 1. That is, the input shaft 1, the carrier 23, and the external gear 24 can all freely and smoothly rotate arbitrarily (including forward rotation and reverse rotation) in the rotational direction of the input shaft 1

As shown in fig. 1 and 2, the sun gear 21 is fixed to the input shaft 1 so as to be rotatable simultaneously with the input shaft 1, and the sun gear 21 meshes with the large planetary gear 22a of the planetary gear set 22, whereby when a torque output is input to the input shaft 1 from the resistance source, the input shaft 1 rotates together with the sun gear 21, and the torque output is transmitted to the large planetary gear 22a by the meshing of the sun gear 21 and the large planetary gear 22a. In addition, with respect to the small planetary gear 22b fixed together with the large planetary gear 22a in the planetary gear set 22, it intermeshes with the external gear 24, so that the torque output transmitted to the large planetary gear 22a can be further transmitted to the external gear 24 via the small planetary gear 22b.

Thus, by the cooperative relationship between the sun gear 21 fixed to the input shaft 1, the planetary gear set 22 having the large planetary gear 22a and the small planetary gear 22b, and the carrier 23 and the outer gear 24, torque output from the resistance source can be transmitted, that is, not only differential action can be achieved, but also torque can be increased, and the diameter of the wire winding assembly can be increased, and the number of windings of the wire winding can be reduced.

As shown in fig. 1 and 2, the first spool 3 is fixedly provided to the carrier 23, and the second spool 4 is fixedly provided to the external gear 24, so that the first spool 3 and the second spool 4 can rotate with the rotation of the carrier 23 and the external gear 24, respectively. That is, by providing the first spool 3 and the second spool 4 in the two-stage planetary transmission set 2, independent rotation can be performed using the mating relationship of the two-stage planetary transmission set 2.

Further, as shown in fig. 1, the resistance transmission mechanism further includes a first wire 31 and a second wire 41, the first wire 31 is wound around the first wire spool 3, and the second wire 41 is wound around the second wire spool 4. By providing the first and second wires 31 and 41, when the resistance transmission mechanism is mounted to the exercise apparatus (e.g., when the resistance transmission mechanism is directly mounted to a stand or other apparatus adapted for the resistance transmission mechanism), an exerciser can feel the tensile forces outputted by the first and second wires 31 and 41 by pulling the first and second wires 31 and 41 to satisfy exercise demands.

Next, the torque output of the resistance transmission mechanism of the present invention will be described with reference to fig. 1 and 2.

First, the input shaft 1 of the motor as a resistance source continuously inputs torque, and since the sun gear 21 is fixed to the input shaft 1, the input torque is transmitted to the sun gear 21 via the input shaft 1. Then, the torque transmitted to the sun gear 21 is transmitted to the large planetary gear 22a meshed with the sun gear 21, and simultaneously transmitted to the small planetary gear 22b fixed integrally with the large planetary gear 22a. The torque transmitted to the small planetary gear 22b is then further transmitted to the external gear 24 meshed with the small planetary gear 22b. At this time, the planetary gear set 22 tends to revolve around the input shaft 1 due to the interaction of the sun gear 21, the external gear 24, and the carrier 23 supporting the planetary gear set 22, and this torque can be transmitted to the carrier 23 via the needle shaft 22 c. Therefore, the external gear 24 and the carrier 23 simultaneously output torque under the interaction of the internal components of the two-stage planetary transmission set 2, and the torque may be several times the torque of the input shaft 1 after being decelerated and amplified.

Further, since the first wire spool 3 is disposed on the carrier 23 and the second wire spool 4 is disposed on the external gear 24, the torque output is transmitted to the first wire 31 and the second wire 41 wound thereon, respectively, through the first wire spool 3 and the second wire spool 4, respectively, so that the first wire 31 and the second wire 41 generate a pulling force. At this time, the reduction ratio of the external gear 24 and the carrier 23 with respect to the input shaft 1 is not the same, and hence the output torque is also not the same. In this regard, by designing the diameter ratio of the first spool 3 and the second spool 4, the first wire 31 and the second wire 41 can be made to exhibit the same or similar pulling force. The first spool 3 and the second spool 4 may be rotated independently, simultaneously, or one by one. That is, by the resistance transmission mechanism, the exerciser can feel the tensile force outputted from the first and second wires 31 and 41 in any combination of the first and second wires 31 and 4 being pulled out, contracted or stationary, so as to meet the user's demand.

In addition, the continuous torque provided by the motors transferred to the first and second bobbins 3 and 4 via the two-stage planetary gear set 2 can be further transferred to the first and second wires 31 and 41 wound thereon by designing the diameters of the first and second bobbins 3 and 4, and it can be exhibited that both the first and second wires 31 and 41 have continuous equal or similar pulling forces.

Specifically, the present invention is used in such a manner that the sun gear 21 meshes with the large planetary gear 22a of the planetary gear set 22, and therefore the sun gear 21 and the large planetary gear 22a can rotate while transmitting torque to each other. The large planet 22a and the small planet 22b are fixed together and can transmit torque to each other. The small planetary gear 22b and the external gear 24 are meshed with each other, so that the sun gear 21 can transmit torque to the external gear 24 through the planetary gear set 22, and the sun gear 21 can also transmit torque to the carrier 23 through the meshing with the large planetary gear 22a. Unlike available planetary speed reducing mechanism, the present invention has no ring gear for the operation of the resistance source body, the input shaft, the planetary carrier and the outer gear, and this reduces the manufacture difficulty, cost and noise.

In actual use, the resistance transmission mechanism is mounted on the exercise equipment and comprises the following three operating states: (1) When the exerciser does not apply the tension to the first and second wires 31 and 41 or the applied tension is smaller than the tension exhibited by the first and second wires 31 and 41, the first and second wires 31 and 41 are in a state of being wound around the first and second bobbins 3 and 4, respectively, and the first and second wires 31 and 41 are continuously kept in a taut state and continuously output the tension; (2) When the tension applied to the first and second wires 31 and 41 by the exerciser is greater than the tension exhibited by the first and second wires 31 and 41, the first and second wires 31 and 41 are in a state of being pulled out from the first and second bobbins 3 and 4, respectively, and each wire is kept in a continuously tensioned state and continuously outputs the tension; (3) When the tension applied by the exerciser to the first wire 31 and the second wire 41 is equal to the tension exhibited by the first wire 31 and the second wire 41, the first wire 31, the second wire 41, the first wire spool 3 and the second wire spool 4 are all in a stationary state, and at this time, the wires are still kept in a tight state and continuously output tension.

According to the resistance transmission mechanism, the requirement of double-rope output which can be realized by two motors can be realized by matching one motor with one secondary transmission group, so that the cost is greatly reduced, and compared with the scheme that the two motor output shafts directly wind a pull rope, the resistance transmission mechanism provided by the invention has larger output tension and torque.

In a specific embodiment, the reduction ratio i of the sun gear 21 and the external gear 24 is used ₂₁ ：i ₂₄ The description is given by taking 3.24 as an example (i is the number of rotations). At this time, assuming that the rated output of the motor is 10Nm, i of the external gear 24 ₂₄ The output can reach 32.4Nm, i of the planetary gear set 22 ₂₂ The output may reach 22.4Nm. In contrast, in the case of using a differential mechanism configured using other members such as a bevel gear and a sprocket as in patent document 1, even if a 40Nm motor is used, only 20Nm of torque can be output from the output bevel gear.

Therefore, the invention can realize the requirement of double-rope output which can be realized by two motors usually with smaller rated output only by matching one motor with one secondary transmission group, greatly reduces the cost, saves the resources, and compared with the scheme that the two motor output shafts directly wind the pull rope, the resistance transmission mechanism provided by the invention has larger output tension and torque under the same condition. In addition, not only the number of motors can be reduced, but also the cost of the drivers and the gears and the accessory structures required by the motors can be reduced.

In addition, when manufacturing the ring gear, the manufacturing cost of the single ring gear is generally 10 times or more the manufacturing cost of the single outer ring gear of the same specification. In the invention, the differential mechanism is skillfully designed, and only the outer ring gear is used instead of the structure with the inner ring gear by utilizing the mutual matching between the two-stage transmission group and each gear, so that the use cost can be better reduced. Moreover, the process of manufacturing the outer ring gear member is far simpler than the process of manufacturing the inner ring gear member, so that the manufacturing process can be simplified by the present invention, and complicated ring gear processing can be omitted, thereby further reducing the manufacturing cost. That is, the invention has lower manufacturing precision requirement, fewer parts, lower cost and lower noise

In addition, compared with the differential structure scheme of the movable pulley rope, the resistance transmission mechanism provided by the invention has no risk of pulley rope falling, has higher reliability, and can more conveniently realize the requirements of speed reduction and torque increase.

In addition, the invention adopts the cylindrical gears, compared with the bevel gear differential structure, the structure of the invention is simpler and more compact, synchronous belts and synchronous wheel transmission are not needed, the processing cost of the cylindrical gears is far lower than that of other types of gears such as sector gears and the like, and the easiness of realizing the same processing precision is far lower than that of other gears, so that the higher precision can be realized with lower cost, the cost can be reduced, and the high precision can be realized more easily, and the low noise can be realized more easily.

In addition, compared with a movable pulley rope differential structure, a bevel gear differential structure and a double-motor scheme, the resistance transmission mechanism provided by the invention only occupies a small space, and can realize the resistance transmission requirement of single motor double-wire, so that the installation place is not limited to gymnasiums, and the resistance transmission mechanism can be installed in more places such as houses, offices and leisure places.

While the embodiments of the present invention have been described, those skilled in the art can make various modifications and alterations to the embodiments of the present invention without departing from the spirit and scope of the invention.

Claims

1. A resistance transmission mechanism for an exercise apparatus, comprising:

a resistance source with an input shaft, a two-stage planetary transmission group, a first wire spool and a second wire spool, wherein,

the two-stage planetary transmission group comprises a sun gear, a planetary gear set with a first planetary gear, a second planetary gear and a planetary wheel shaft, a planetary carrier and an external gear,

the sun gear is fixed to the input shaft and intermeshes with the first planet gears,

the external gear is rotatably sleeved on the input shaft and meshed with the second planetary gear,

the first planetary gear and the second planetary gear have different diameters, are fixed on the planetary wheel shaft and are rotatably arranged on the planetary frame,

the first wire spool is arranged on the planet carrier, and the second wire spool is arranged on the outer gear.

2. The drag transmission mechanism of claim 1, wherein,

the sun gear, the first planetary gear, the second planetary gear and the external gear are cylindrical gears.

3. The drag transmission mechanism of claim 2, wherein,

the wire winding device further comprises a first wire and a second wire, wherein the first wire is wound on the first wire spool, and the second wire is wound on the second wire spool.

4. A drag transmission mechanism as claimed in any one of claims 1 to 3, wherein,

one of the first planet wheel and the second planet wheel is provided with a shaft sleeve and is arranged on the planet wheel shaft through two planet wheel bearings, the other of the first planet wheel and the second planet wheel is arranged on the shaft sleeve through a combination part, and the planet wheel shaft is arranged in the mounting hole of the planet carrier in a penetrating mode.

5. A drag transmission mechanism as claimed in any one of claims 1 to 3, wherein,

the first planet wheel and the second planet wheel are respectively arranged on the planet wheel shaft through a planet wheel bearing, and the planet wheel shaft is arranged in the mounting hole of the planet carrier in a penetrating mode.

6. The drag transmission mechanism of claim 4 or 5,

the gear assembly further comprises a second bearing sleeved on the radial outer side of one end of the input shaft and clamped on the radial inner side of the external gear, and the external gear is mounted on the input shaft through the second bearing.

7. The drag transmission mechanism of claim 6, wherein,

the planetary gear set comprises an input shaft, a planetary carrier, a first bearing, a third bearing, a first bearing, a second bearing, a third bearing, a planetary carrier and a planetary gear set, wherein the first bearing is sleeved on the radial outer side of the external gear, the third bearing is sleeved on the radial outer side of the other end of the input shaft, and the planetary carrier is mounted on the planetary gear set through the first bearing and the third bearing.

8. The drag transmission mechanism of claim 7,

the number of the second bearings is two, and the number of the first bearings and the number of the third bearings are one.

9. The drag transmission mechanism of claim 6, wherein,

the planetary gear bearing is a needle roller bearing, and the planetary gear shaft is a needle roller shaft.