CN220248872U - Shaft body assembly structure, gear transmission module, planetary gear mechanism and speed reducer - Google Patents

Abstract

The application provides a shaft body assembly structure, gear drive module, planet wheel mechanism and reduction gear relates to gear drive technical field. The shaft body assembly structure comprises an installation base frame, a fixed shaft and an elastic cylindrical pin; the mounting base frame is provided with an assembly hole, and the outer peripheral surface of the mounting base frame is provided with a first pin shaft hole; the fixed shaft is arranged in the assembly hole, a second pin shaft hole is formed in the fixed shaft along the radial direction of the fixed shaft, the second pin shaft hole and the first pin shaft are coaxially arranged, and the fixed shaft is used for mounting a transmission gear; the cylindrical pin is connected with the first pin shaft hole and the second pin shaft hole in a penetrating way; the end of the first pin shaft hole, which is close to the second pin shaft hole, is a first orifice end, the end of the second pin shaft hole, which is close to the first pin shaft hole, is a second orifice end, and a transition curved surface is arranged on the edge part of the first orifice end in a ring manner and/or a transition curved surface is arranged on the edge part of the second orifice end in a ring manner. The application provides a shaft body assembly structure reduces the inefficacy risk of elasticity cylindric lock, increase of service life.

Description

Shaft body assembly structure, gear transmission module, planetary gear mechanism and speed reducer

Technical Field

The application relates to the technical field of gear transmission, in particular to a shaft body assembly structure, a gear transmission module, a planetary gear mechanism and a speed reducer.

Background

The planetary assembly is widely applied to a planetary gear train and is quite common in the field of engineering machinery and the field of automobiles. Common planetary assemblies include: the planetary gear comprises a planetary carrier, planetary gears, planetary shafts, rolling pins, gaskets, elastic cylindrical pins and the like. The planet carrier is used as a frame of the whole assembly, and the volume ratio is the largest; the planet gears realize motion transmission through the meshing of gears; the planet axle is as the dead axle that the planet wheel rotated around, needs to be fixed with the planet carrier, and the common fixed mode: the planet shaft and the planet carrier are provided with holes and are connected through an elastic cylindrical pin.

In practical application, the elastic cylindrical pin at the joint surface of the planet shaft and the planet carrier is easy to be subjected to shearing force, and when the excessive shearing force acts on the elastic cylindrical pin in the operation process, the elastic cylindrical pin collides with the hole wall of the pin hole to deform or even cause fracture, so that the service life of the planet assembly is seriously influenced.

Disclosure of Invention

An object of the application is to provide a shaft body assembly structure, gear drive module, planet wheel mechanism and reduction gear for solve the not enough that exists among the prior art.

To achieve the above object, in a first aspect, the present application provides a shaft body assembly structure, including:

the mounting base frame is provided with an assembly hole, the outer circumferential surface of the mounting base frame is provided with a first pin shaft hole, and the first pin shaft hole extends to the inner wall surface of the assembly hole along the radial direction of the assembly hole;

the fixed shaft is arranged on the mounting base frame and is positioned in the assembly hole, a second pin shaft hole is formed in the fixed shaft along the radial direction of the fixed shaft, the second pin shaft hole is coaxially arranged with the first pin shaft, and the fixed shaft is used for mounting a transmission gear; and

the cylindrical pin is connected with the first pin shaft hole and the second pin shaft hole in a penetrating way;

the end, close to the second pin shaft hole, of the first pin shaft hole is a first orifice end, the end, close to the first pin shaft hole, of the second pin shaft hole is a second orifice end, a transition curved surface is arranged on the edge part of the first orifice end in a ring mode, and/or a transition curved surface is arranged on the edge part of the second orifice end in a ring mode.

As a further improvement of the above technical scheme:

with reference to the first aspect, in a possible implementation manner, the transition curved surface is formed with a transition curve along a section of the first pin shaft hole or the second pin shaft hole in an axial direction, and the transition curve is tangent to a hole wall of the corresponding first pin shaft hole or the second pin shaft hole.

With reference to the first aspect, in a possible implementation manner, the transition curve is an arc.

With reference to the first aspect, in a possible implementation manner, the transition curve includes a first transition section and a second transition section connected in sequence;

the first transition section is connected with the corresponding hole wall in a tangential mode, the first transition section is an arc line, and the second transition section is a straight line.

With reference to the first aspect, in a possible implementation manner, the transition curve includes a first transition section, a second transition section, and a third transition section that are sequentially connected;

the first transition section is in tangent connection with the corresponding hole wall, the first transition section is an arc line, the second transition section is a straight line, and the third transition section is an arc line or a straight line.

In order to achieve the above object, in a second aspect, the present application further provides a gear transmission module, including a transmission gear and the shaft assembly structure provided according to the above first aspect, the transmission gear is rotatably disposed on the fixed shaft.

As a further improvement of the above technical scheme:

with reference to the second aspect, in a possible implementation manner, a needle bearing is disposed between the transmission gear and the fixed shaft.

With reference to the second aspect, in one possible implementation manner, the fixed shaft is provided with a first lubrication channel along an axis direction of the fixed shaft, and is further provided with a second lubrication channel along a radial direction of the fixed shaft, one end of the second lubrication channel is connected with the first lubrication channel, and the other end of the second lubrication channel is communicated with a gap between the transmission gear and the fixed shaft, wherein the needle bearing is installed between the transmission gear and the fixed shaft.

To achieve the above object, in a third aspect, the present application further provides a planetary gear mechanism, including the gear transmission module provided according to the above second aspect, wherein the mounting base frame is a planet carrier, the fixed shaft is a planet shaft, and the transmission gear is a planetary gear.

To achieve the above object, in a fourth aspect, the present application further provides a speed reducer including the planetary gear mechanism provided according to the above third aspect.

Compared with the prior art, the beneficial effect of this application:

the application provides a shaft body assembly structure, gear drive module, planet wheel mechanism and reduction gear, wherein, shaft body assembly structure wears to link first round pin shaft hole and second round pin shaft hole through the cylindric lock, realizes the fixed axle and installs the connection of bed frame to the edge through at first drill way end is equipped with transition curved surface and/or the edge of second drill way end is equipped with transition curved surface in the ring. According to stress analysis, the stress distribution condition of the first orifice end and/or the second orifice end can be obviously improved through the arranged transition curved surface structure, and meanwhile, the shearing stress of the fixed shaft to the cylindrical pin at the joint surface of the mounting base frame is reduced, so that the stress distribution of the cylindrical pin is greatly improved, the collision deformation and fracture failure risk of the cylindrical pin and the hole wall is reduced, and the service life of the shaft body assembly structure is prolonged.

Additional features and advantages of the present application will be set forth in the detailed description which follows.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate only some embodiments of the application and are therefore not to be considered limiting of its scope, for the purpose of providing additional related drawings from which the utility model may be practiced by those of ordinary skill in the art without the exercise of inventive faculty. In the drawings:

fig. 1 shows a schematic structural view of a shaft assembly structure according to an embodiment of the present application;

FIG. 2 shows an enlarged schematic view of a first partial structure at A in FIG. 1;

fig. 3 shows stress distribution diagrams of a shaft body assembly structure (a) provided with no transition curved surface and a shaft body assembly structure (b) provided with a circular arc transition curved surface according to an embodiment of the present application;

fig. 4 shows a stress cloud chart of an elastic cylindrical pin (a) of a shaft assembly structure without a transition curved surface and an elastic cylindrical pin (b) of a shaft assembly structure with a circular arc transition curved surface, provided in an embodiment of the present application;

fig. 5 shows a stress distribution graph in the length direction of an elastic cylindrical pin of a shaft body assembly structure without a transition curved surface and an elastic cylindrical pin of a shaft body assembly structure with a circular arc transition curved surface, which are provided in an embodiment of the present application;

FIG. 6 shows an enlarged schematic view of a second partial structure at A in FIG. 1;

FIG. 7 shows an enlarged schematic view of a third partial structure at A in FIG. 1;

fig. 8 shows a schematic structural diagram of a gear transmission module according to an embodiment of the present disclosure;

fig. 9 shows a schematic perspective view of a planetary gear mechanism according to an embodiment of the present application.

Reference numerals illustrate:

100. installing a base frame; 100a, a planet carrier; 101. a frame body; 110. a first pin hole; 111. a first orifice end; 120. positioning a gasket;

200. a fixed shaft; 200a, planetary shaft; 210. a second pin hole; 211. a second orifice end; 220. a transition curve; 221. a first transition section; 222. a second transition section; 223. a third transition section; 230. a first lubrication channel; 240. a second lubrication channel;

300. a cylindrical pin;

400. a transmission gear; 400a, planet wheels;

500. needle roller bearings.

Detailed Description

The following describes in detail the implementation of the embodiments of the present application with reference to the accompanying drawings. It should be understood that the detailed description is presented herein by way of illustration and explanation of the present application examples, and is not intended to limit the present application examples.

It should be noted that, in the case of no conflict, the embodiments and features in the embodiments may be combined with each other.

In the embodiments of the present application, 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", "axial", "radial", "circumferential", 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 application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

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 such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In this application, unless specifically stated and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; 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 terms in this application will be understood by those of ordinary skill in the art as the case may be.

The present application will be described in detail below with reference to the attached drawings in conjunction with exemplary embodiments.

Example 1

Referring to fig. 1 and 2, the present embodiment provides a shaft assembly structure, which is particularly applicable to a gear transmission module.

In this embodiment, the shaft body assembly structure includes a mounting base frame 100, a fixing shaft 200, and a cylindrical pin 300. Wherein, the mounting base frame 100 is provided with an assembly hole (not shown), the outer circumferential surface of the mounting base frame 100 is provided with a first pin shaft hole 110, and the first pin shaft hole 110 extends to the inner wall surface of the assembly hole along the radial direction of the assembly hole.

The fixing shaft 200 is installed in the installation base frame 100 and is located in the assembly hole, the fixing shaft 200 is provided with a second pin shaft hole 210 in a radial direction thereof, the second pin shaft hole 210 is coaxially arranged with the first pin shaft hole 110, and the fixing shaft 200 is used for installing a transmission gear 400 in a gear transmission module (refer to fig. 8).

Optionally, the fixing shaft 200 is in an interference fit with the assembly hole.

The cylindrical pin 300 passes through the first pin shaft hole 110 and the second pin shaft hole 210, that is, one part of the cylindrical pin 300 is positioned in the first pin shaft hole 110, and the other part is positioned in the second pin shaft hole 210. Thus, the relative movement between the fixing shaft 200 and the mounting base frame 100 can be restricted by the cylindrical pin 300, so that a fixed fit is formed between the fixing shaft 200 and the mounting base frame 100.

Referring to fig. 2, an end of the first pin shaft hole 110 near the second pin shaft hole 210 is a first orifice end 111, and an end of the second pin shaft hole 210 near the first pin shaft hole 110 is a second orifice end 211. In the present embodiment, the edge of the second orifice end 211 is provided with a transition curved surface.

It can be appreciated that the second pin shaft hole 210 has a hole wall, and the transition curved surface can smoothly transition the hole wall of the second pin shaft hole 210 and the outer circumferential surface of the fixed shaft 200, so as to effectively improve the stress distribution condition of the second hole end 211.

When the transmission gear 400 works, as shown by the stress analysis, under the condition of improving the stress distribution of the second orifice end 211, the shearing stress of the fixing shaft 200 to the cylindrical pin 300 at the joint surface of the mounting base frame 100 is reduced, so that the stress distribution of the cylindrical pin 300 is greatly improved, the risk of collision deformation and fracture between the cylindrical pin 300 and the hole wall is reduced, and the service life of the long shaft assembly structure is prolonged.

In some embodiments, a transition curved surface may be disposed around the edge of the first orifice end 111 of the first pin shaft hole 110, and the first pin shaft hole 110 also has a hole wall, and the transition curved surface may enable the hole wall of the first pin shaft hole 110 to smoothly transition with the inner wall surface of the assembly hole, so as to effectively improve the stress distribution condition of the first orifice end 111. Therefore, the shearing stress of the fixing shaft 200 to the cylindrical pin 300 at the joint surface of the mounting base frame 100 can be reduced, so that the stress distribution of the cylindrical pin 300 is greatly improved, the risk of collision deformation and fracture of the cylindrical pin 300 and the hole wall is reduced, and the service life of the long shaft body assembly structure is prolonged.

In still other embodiments, a transition curve may also be looped around the edge of the first bore end 111 of the first pin bore 110, while a transition curve may be looped around the edge of the second bore end 211.

Example two

Referring to fig. 1 and 2, the present embodiment provides a shaft assembly structure. The present embodiment is an improvement on the technical basis of the first embodiment described above, and is different from the first embodiment described above in that:

in this embodiment, a transitional curved surface is formed around the edge of the second orifice end 211, which is specifically as follows:

the cylindrical pin 300 is selected as an elastic cylindrical pin, and a transition curve 220 is formed on the transition curve along the section of the second pin shaft hole 210 in the axial direction, wherein the transition curve 220 formed by the transition curve is tangential to the hole wall of the second pin shaft hole 210.

In some embodiments, the transition curve 220 is an irregular curve.

In this embodiment, the transition curve 220 is an arc. To facilitate processing.

In some embodiments, the radius R of the arc is 1-2 mm.

In other embodiments, the radius R of the arc is 1.5-2 mm.

Alternatively, the radius R of the circular arc may also be selected to be 1.54mm, 1.6mm, 1.65mm, 1.68mm, 1.72mm, 1.79mm, 1.83mm, 1.85mm, 1.9mm, 1.95mm or 1.98mm. It should be understood that the radius R of the arc may also be adjusted according to the size of the second pin hole 210, which is only illustrated and not limiting to the scope of the present application.

Referring to fig. 3, fig. 4 and fig. 5 together, for a clearer description of the technical solution of the present embodiment, in the case of equal loading, by performing simulation analysis on the shaft assembly structure provided in the present embodiment (the second orifice end 211 is provided with a transition curved surface, the transition curved surface is an arc) and the shaft assembly structure in the prior art (the second orifice end 211 is defined as a sharp corner), the stress improvement condition is illustrated by using the stress distribution of the second pin hole 210 and the elastic cylindrical pin 300 in the radial direction of the fixed shaft 200 as a criterion, and the specific analysis is as follows:

1) Load is applied to the shaft body assembling structure and acts on the center position where the fixed shaft 200 is engaged with the transmission gear 400, simulating the radial force of gear engagement.

2) Referring to fig. 3, fig. 3 (b) and fig. 3 (a) are respectively stress distribution diagrams of the present embodiment at the radial second pin hole 210 of the fixing shaft 200 compared with the prior art. As can be seen from the figure: at the radial position of the second pin shaft hole 210 of the fixed shaft 200, the stress improvement after the second pin shaft hole 210 of the embodiment is provided with a circular arc transition curved surface is obvious, and the maximum stress is reduced by about 56%; similarly, comparing the stress distribution of the elastic cylindrical pins 300 with the two structures, it was also found that the stress applied to the elastic cylindrical pins 300 in this embodiment is significantly smaller than that in the prior art.

3) Referring to fig. 4, fig. 4 (a) and fig. 4 (b) are stress cloud diagrams comparing the elastic cylindrical pin 300 in the conventional structure (the second orifice end 211 is a sharp corner) and the present embodiment (the second orifice end 211 is an arc), respectively. From fig. 4, it can be seen that: the stress concentration at the middle position (corresponding to the joint surface of the fixed shaft 200 and the mounting base frame 100) of the elastic cylindrical pin 300 under the sharp angle is obvious; referring to fig. 5, the comparison of the stresses extracted from the middle surface of the elastic cylindrical pin 300 shows that the maximum stress is significantly reduced by about 27% compared with the sharp corner under the arc-shaped transition curved surface.

It should be noted that, when the edge portion of the first orifice end 111 of the first pin hole 110 is looped with a transition curved surface, the above description of the transition curved surface of the second orifice end 211 is equally applicable to the transition curved surface of the first orifice end 111.

Example III

Referring to fig. 1 and 6, the present embodiment provides a shaft assembly structure. The present embodiment is an improvement on the technical basis of the first embodiment described above, and is different from the first embodiment described above in that:

in this embodiment, a transitional curved surface is formed around the edge of the second orifice end 211, which is specifically as follows:

the transition curve 220 formed by the transition curved surface includes a first transition section 221 and a second transition section 222 connected in sequence along the section of the axial direction of the second pin hole 210.

The first transition section 221 is tangentially connected with the corresponding hole wall, the first transition section 221 is an arc line, and the second transition section 222 is a straight line.

Optionally, the first transition 221 and the second transition 222 are tangentially connected. It should be noted that, when the edge portion of the first orifice end 111 of the first pin hole 110 is looped with a transition curved surface, the above description of the transition curved surface of the second orifice end 211 is equally applicable to the transition curved surface of the first orifice end 111.

Example IV

Referring to fig. 1 and 7, the present embodiment provides a shaft assembly structure. The present embodiment is an improvement on the technical basis of the first embodiment described above, and is different from the first embodiment described above in that:

in this embodiment, a transitional curved surface is formed around the edge of the second orifice end 211, which is specifically as follows:

the transition curve 220 formed by the transition curved surface includes a first transition section 221, a second transition section 222, and a third transition section 223 connected in sequence along the section of the axial direction of the second pin hole 210.

The first transition section 221 is tangentially connected with the corresponding hole wall, the first transition section 221 is an arc, the second transition section 222 is a straight line, and the third transition section 223 is an arc or a straight line.

In some embodiments, third transition 223 is an arc, wherein first transition 221, second transition 222, and third transition 223 are sequentially tangentially connected.

In other embodiments, the third transition 223 is a straight line, wherein the first transition 221 and the second transition 222 are tangentially connected. It should be noted that, when the edge portion of the first orifice end 111 of the first pin hole 110 is looped with a transition curved surface, the above description of the transition curved surface of the second orifice end 211 is equally applicable to the transition curved surface of the first orifice end 111.

Example five

Referring to fig. 1 and 8, the present embodiment provides a gear transmission module. The gear transmission module includes a transmission gear 400 and the shaft assembly structure provided according to any one of the above embodiments, and the transmission gear 400 is rotatably disposed on the fixed shaft 200.

Specifically, a needle bearing 500 is provided between the transmission gear 400 and the fixed shaft 200. The needle in the needle bearing 500 takes the inner hole of the transmission gear 400 as an outer raceway and the outer circular surface of the fixed shaft 200 as an inner raceway, thereby realizing the fixed shaft rotation of the transmission gear 400.

Further, the mounting base frame 100 includes two frame bodies 101 arranged opposite to each other, the fixing shaft 200 is arranged through the two frame bodies 101, and the transmission gear 400 is located between the two frame bodies 101. Wherein, the two sides of the transmission gear 400 are respectively provided with a positioning gasket 120 sleeved on the fixed shaft 200, and the positioning gaskets 120 are abutted with the corresponding side of the frame body 101. Thereby, the axial positioning of the transmission gear 400 on the fixed shaft 200 is achieved by the positioning washer 120.

In this embodiment, the fixed shaft 200 is provided with a first lubrication channel 230 along the axial direction thereof, the fixed shaft 200 is further provided with a second lubrication channel 240 along the radial direction thereof, one end of the second lubrication channel 240 is connected with the first lubrication channel 230, and the other end is communicated with a gap between the transmission gear 400 and the fixed shaft 200 in which the needle bearing 500 is mounted. Thereby providing lubrication oil to the needle bearing 500 through the first lubrication channel 230 and the second lubrication channel 240 to meet the lubrication requirements of the needle bearing 500.

Example six

Referring to fig. 1, 8 and 9, the present embodiment provides a planetary gear mechanism, which includes the gear transmission module provided in the fifth embodiment. The mounting base frame 100 is a planet carrier 100a, the fixed shaft 200 is a planet shaft 200a, and the transmission gear 400 is a planet gear 400a.

Further, the embodiment also provides a speed reducer, which comprises the planetary gear mechanism provided by the embodiment.

It should be noted that, in the first-stage planetary gear mechanism, since the planetary shaft 200a is hardened, the hardness is higher than that of the cylindrical pin 300, so that the cylindrical pin 300 is liable to fail. Therefore, the gear transmission module provided in the fifth embodiment can effectively reduce the risk of failure of the cylindrical pin 300.

The foregoing details of the optional implementation manner of the embodiment of the present application have been described in detail with reference to the accompanying drawings, but the embodiment of the present application is not limited to the specific details of the foregoing implementation manner, and various simple modifications may be made to the technical solution of the embodiment of the present application within the scope of the technical concept of the embodiment of the present application, and these simple modifications all belong to the protection scope of the embodiment of the present application.

In addition, the specific features described in the foregoing embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various possible combinations are not described in detail in this application.

Moreover, any combination of the various embodiments of the present application may be made, so long as it does not deviate from the idea of the embodiment of the present application, and it should also be regarded as the disclosure of the embodiment of the present application.

Claims (10)

1. A shaft body assembly structure, comprising:

the mounting base frame (100), the mounting base frame (100) is provided with an assembly hole, the outer peripheral surface of the mounting base frame (100) is provided with a first pin shaft hole (110), and the first pin shaft hole (110) extends to the inner wall surface of the assembly hole along the radial direction of the assembly hole;

the fixed shaft (200) is arranged on the mounting base frame (100) and is positioned in the assembly hole, a second pin shaft hole (210) is formed in the fixed shaft (200) along the radial direction of the fixed shaft, the second pin shaft hole (210) and the first pin shaft hole (110) are coaxially arranged, and the fixed shaft (200) is used for mounting a transmission gear (400); and

a cylindrical pin (300) passing through the first pin hole (110) and the second pin hole (210);

the end, close to the second pin shaft hole (210), of the first pin shaft hole (110) is a first orifice end (111), the end, close to the first pin shaft hole (110), of the second pin shaft hole (210) is a second orifice end (211), a transition curved surface is arranged on the edge part ring of the first orifice end (111) and/or a transition curved surface is arranged on the edge part ring of the second orifice end (211).

2. The shaft body assembly structure according to claim 1, wherein the transition curved surface is formed with a transition curve (220) along a section of the first pin shaft hole (110) or the second pin shaft hole (210) in an axial direction, the transition curve (220) being tangential to a wall of the corresponding first pin shaft hole (110) or the second pin shaft hole (210).

3. The shaft assembly structure of claim 2, wherein the transition curve is an arc.

4. The shaft assembly structure according to claim 2, wherein the transition curve (220) comprises a first transition section (221) and a second transition section (222) connected in sequence;

the first transition sections (221) are connected with the corresponding hole walls in a tangential mode, the first transition sections (221) are arc lines, and the second transition sections (222) are straight lines.

5. The shaft assembly structure according to claim 2, wherein the transition curve (220) comprises a first transition section (221), a second transition section (222) and a third transition section (223) connected in sequence;

the first transition sections (221) are connected with the corresponding hole walls in a tangential mode, the first transition sections (221) are arc lines, the second transition sections (222) are straight lines, and the third transition sections (223) are arc lines or straight lines.

6. A gear transmission module comprising a transmission gear (400) and a shaft assembly structure according to any one of claims 1-5, said transmission gear (400) being rotatably arranged on said stationary shaft (200).

7. The gear transmission module according to claim 6, characterized in that a needle bearing (500) is provided between the transmission gear (400) and the stationary shaft (200).

8. The gear transmission module according to claim 7, wherein the fixed shaft (200) is provided with a first lubrication channel (230) along the axis direction thereof, the fixed shaft (200) is further provided with a second lubrication channel (240) along the radial direction thereof, one end of the second lubrication channel (240) is connected with the first lubrication channel (230), and the other end is communicated with a gap between the transmission gear (400) and the fixed shaft (200) where the needle bearing (500) is installed.

9. A planetary gear mechanism, characterized by comprising a gear transmission module according to any of claims 6-8, wherein the mounting base frame (100) is a planet carrier (100 a), the stationary shaft (200) is a planet shaft (200 a), and the transmission gear (400) is a planet wheel (400 a).

10. A reducer comprising a planetary gear mechanism according to claim 9.