CN111963668A

CN111963668A - Planetary gear speed reduction transmission structure and speed reducer with same

Info

Publication number: CN111963668A
Application number: CN202010727582.9A
Authority: CN
Inventors: 蒋浩; 吕刚; 王飞飞; 沈超; 叶林
Original assignee: Jiangsu Guomao Reducer Group Co ltd
Current assignee: Jiangsu Guomao Reducer Group Co ltd
Priority date: 2020-07-21
Filing date: 2020-07-21
Publication date: 2020-11-20
Anticipated expiration: 2040-07-21
Also published as: CN111963668B

Abstract

The invention discloses a planetary gear speed reduction transmission structure and a speed reducer with the same, which mainly comprise: planet wheel, the sun gear, internal gear and planet carrier subassembly, wherein the planet carrier subassembly includes first planet carrier, second planet carrier and connecting plate, the connecting plate both sides are located to first planet carrier and second planet carrier symmetry, the one end and the first planet carrier of sun gear rotate to be connected, the other end and the second planet carrier of sun gear rotate to be connected, the one end and the first planet carrier of planet wheel rotate to be connected, the other end and the second planet carrier of planet wheel rotate to be connected, the planet wheel meshes with the sun gear mutually, the connecting plate outside is located to the internal gear cover, the planet wheel meshes with the internal gear mutually. The first planet carrier and the second planet carrier are symmetrically fixed on two sides of the connecting plate through bolts, so that two ends of a planet wheel are supported, and the planet wheel is convenient to mount and replace; the input shaft is fixedly connected with the sun gear through the connecting gear sleeve, so that the sun gear is convenient to disassemble and replace.

Description

Planetary gear speed reduction transmission structure and speed reducer with same

Technical Field

The invention relates to the technical field of speed reducers, in particular to a planetary gear speed reduction transmission structure and a speed reducer with the same.

Background

With the continuous development of the speed reducer industry, more and more enterprises use the speed reducer, and the planetary speed reducer is an industrial product. The planetary reducer is widely applied to transmission systems such as servo, stepping and direct current due to small volume, high transmission efficiency, wide speed reduction range and high precision. On the premise of ensuring precise transmission, the device is mainly used for reducing the rotating speed, increasing the torque and reducing the rotational inertia ratio of a load motor.

The planet carrier of common installation planet wheel is a slice body frame erection column, and this kind of planet carrier intensity is low, because only one side has the support, so the planet wheel atress is inhomogeneous, and current planetary reducer is actually more complicated to the speed governing, leads to the increase of speed reducer volume.

Disclosure of Invention

Objects of the invention

In order to overcome at least one defect of the prior art, the first planet carrier and the second planet carrier are symmetrically fixed on two sides of the connecting plate respectively through bolts, so that two ends of a planet wheel are supported, and the planet wheel is convenient to mount and replace; the input shaft is fixedly connected with the sun gear through the connecting gear sleeve, so that the sun gear is convenient to disassemble and replace; the output shaft and the sun wheel are abutted through the jacking ball and the jacking block, so that friction is reduced, and the output shaft can rotate more smoothly; the first positioning pin is used for fixing the inner gear and the shell, and the second positioning pin is used for fixing the inner gear and the planet carrier, so that the conversion between single-stage speed regulation and two-stage speed regulation is realized.

(II) technical scheme

As a first aspect of the present invention, there is disclosed a planetary gear reduction transmission structure comprising: the planet wheel, the sun wheel, the inner gear and the planet carrier assembly;

the planet carrier assembly comprises a first planet carrier, a second planet carrier and a connecting plate, and the first planet carrier and the second planet carrier are symmetrically arranged on two sides of the connecting plate;

one end of the sun gear is rotationally connected with the first planet carrier, the other end of the sun gear is rotationally connected with the second planet carrier, and the axis of the sun gear is superposed with the central lines of the first planet carrier and the second planet carrier;

one end of the planet wheel is rotationally connected with the first planet carrier, the other end of the planet wheel is rotationally connected with the second planet carrier, and the planet wheel is meshed with the sun wheel;

the internal gear is sleeved on the outer side of the connecting plate, and the planet wheel is meshed with the internal gear.

In a possible embodiment, the first planet carrier and the second planet carrier are symmetrically fixed on two sides of the connecting plate through bolts.

In a possible implementation manner, the transmission structure further includes an input shaft, a connecting shaft is fixedly arranged on one end face of the sun gear, a connecting gear sleeve is arranged on the connecting shaft, and the connecting gear sleeve is used for fixedly connecting the input shaft to the connecting shaft.

In a possible embodiment, at least one first limiting strip is fixedly arranged in the connecting gear sleeve, a second limiting strip abutted against the first limiting strip is fixedly arranged on the connecting shaft, and a third limiting strip abutted against the first limiting strip is fixedly arranged on the input shaft.

In a possible implementation manner, a retainer ring is fixedly arranged on the input shaft, and the retainer ring is fixedly arranged at one end of the third limiting strip, which is far away from the sun gear.

In a possible implementation manner, the transmission structure comprises an output shaft, a top block is arranged on the other end face of the sun gear, a top ball is arranged on one side face, close to the sun gear, of the output shaft, and the top ball is abutted to the top block.

In a possible embodiment, the second planet carrier is provided with a first mounting hole.

In a possible implementation manner, one end of the output shaft is provided with a mounting disc, and the mounting disc is provided with a second mounting hole corresponding to the first mounting hole.

As a second aspect of the present invention, the present invention discloses a speed reducer, comprising: the planetary gear speed reduction transmission mechanism comprises a shell, a planetary gear speed reduction transmission structure and a first positioning pin, wherein the first positioning pin penetrates through the shell and is abutted against an internal gear;

the planetary gear speed reduction transmission structure is any one of the planetary gear speed reduction transmission structures.

In a possible embodiment, the speed reducer further includes a second positioning pin, and the second positioning pin penetrates through the internal gear and abuts against the connecting plate.

(III) advantageous effects

The invention discloses a planetary gear speed reduction transmission structure and a speed reducer with the same, which have the following beneficial effects:

1. the first planet carrier and the second planet carrier are symmetrically fixed on two sides of the connecting plate through bolts respectively, and then the planet wheel is rotatably connected between the first planet carrier and the second planet carrier, so that the planet wheel is convenient to mount and replace.

2. The input shaft is connected with the sun gear through the connecting gear sleeve, the sun gear is convenient to detach and replace, and the retainer ring is arranged on the input shaft and used for limiting the connecting rack.

3. The output shaft is provided with a jacking ball, the sun gear is provided with a jacking block, and the jacking ball is abutted against the jacking block, so that the friction between the output shaft and the sun gear is reduced, the rotation of the output shaft is smoother, and the structure is compact.

4. The first mounting hole is formed in the second planet carrier, and the second mounting hole is formed in the mounting disc of the input shaft, so that the input shaft and the output shaft can be conveniently positioned and mounted, and the axis of the output shaft of the input shaft is overlapped with the axis of the input shaft.

5. The inner gear of the speed reducer is fixedly connected with the shell through the first positioning pin, so that two-stage speed reduction of the speed reducer is realized, the inner gear of the speed reducer is fixedly connected with the planet carrier through the second positioning pin, so that single-stage speed reduction of the speed reducer is realized, the speed reduction of the speed reducer is convenient to adjust by adjusting the positions of the first positioning pin and the second positioning pin, and then the conversion of the single-stage speed reduction and the two-stage speed reduction is realized.

Drawings

The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining and illustrating the present invention and should not be construed as limiting the scope of the present invention.

FIG. 1 is a schematic three-dimensional structure of a planetary gear reduction transmission structure disclosed by the invention;

FIG. 2 is a cross-sectional view A-A of FIG. 1;

FIG. 3 is a schematic illustration of a three-dimensional configuration of the disclosed planet carrier assembly member;

FIG. 4 is a schematic three-dimensional structure of a connecting shaft, a connecting sleeve and an input shaft according to the present disclosure;

FIG. 5 is a schematic three-dimensional structure of the disclosed connecting sleeve gear;

FIG. 6 is a schematic view of an enlarged view at B in FIG. 1;

FIG. 7 is a schematic three-dimensional structure of a heading ball and a heading block disclosed herein;

FIG. 8 is a schematic three-dimensional illustration of the output shaft to planet carrier assembly of the present disclosure;

FIG. 9 is a schematic three-dimensional structure diagram of a first embodiment of a speed reducer disclosed by the invention;

FIG. 10 is a cross-sectional view C-C of FIG. 9;

FIG. 11 is an enlarged schematic view at D of FIG. 10;

FIG. 12 is a schematic three-dimensional structure diagram of a speed reducer disclosed in the present invention;

FIG. 13 is a cross-sectional view of E-E of FIG. 12;

fig. 14 is an enlarged schematic view at F in fig. 13.

Reference numerals: 100. a planet wheel; 200. a sun gear; 210. a top block; 220. a connecting shaft; 221. a second limit strip; 300. an internal gear; 400. a planet carrier assembly member; 410. a first carrier; 420. a second planet carrier; 421. a first mounting hole; 430. a connecting plate; 500. an input shaft; 510. a third limiting strip; 520. a retainer ring; 600. connecting a gear sleeve; 610. a first limit strip; 700. an output shaft; 710. ejecting the ball; 720. mounting a disc; 721. a second mounting hole; 800. a housing; 810. a first positioning pin; 820. and a second positioning pin.

Detailed Description

In order to make the implementation objects, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention will be described in more detail below with reference to the accompanying drawings in the embodiments of the present invention.

It should be noted that: in the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described are some embodiments of the present invention, not all embodiments, and features in embodiments and embodiments in the present application may be combined with each other without conflict. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be taken as limiting the scope of the present invention.

A first embodiment of a planetary gear reduction transmission structure of the present disclosure is described in detail below with reference to fig. 1 to 8. The embodiment is mainly applied to a speed reducer, the first planet carrier and the second planet carrier are symmetrically fixed on two sides of the connecting plate through bolts, so that two ends of a planet wheel of the speed reducer are supported, and the planet wheel is convenient to mount and replace; the input shaft is fixedly connected with the sun gear through the connecting gear sleeve, so that the sun gear is convenient to disassemble and replace; the output shaft and the sun wheel are abutted through the jacking ball and the jacking block, so that friction is reduced, and the output shaft can rotate more smoothly; the first positioning pin is used for fixing the internal gear and the shell, and the second positioning pin is used for fixing the internal gear and the planet carrier, so that conversion between single-stage speed regulation and two-stage speed regulation is realized.

As shown in fig. 1 to 3, the present embodiment mainly includes a planetary gear 100, a sun gear 200, an internal gear 300, and a planetary carrier assembly 400.

The axis of sun gear 200 and the axis coincidence of internal gear 300, the internal gear 300 cover establish with the sun gear 200 outside, planet wheel 100 evenly is equipped with 3 along sun gear 200 axis circumference, and every planet wheel 100 all meshes with sun gear 200, internal gear 300 mutually to accomplish two-stage speed reduction.

As shown in fig. 3, in which the planet gears 100 are rotatably connected to the planet carrier assembly 400, the planet carrier assembly 400 includes a first planet carrier 410, a second planet carrier 420 and a connecting plate 430, and the first planet carrier 410 and the second planet carrier 420 are symmetrically disposed on two sides of the connecting plate 430, so that the planet gears 100 can be conveniently installed and replaced, and the two ends of the planet gears 100 are supported, thereby preventing the planet gears 100 from being broken due to one side being stressed.

The first planet carrier 410 is triangular, and the intersection point of every two intersecting first planet carriers is provided with an arc chamfer, the center of the first planet carrier 410 is provided with a center hole, and a first bearing is arranged in the center hole and used for mounting the sun gear 200. Through holes are uniformly formed in the first planet carrier 410 along the axis of the central hole in the circumferential direction, second bearings are arranged in the through holes and used for mounting the planet wheels 100, and the number of the through holes is equal to that of the planet wheels 100. The second planet carrier 420 is identical in structure, size and shape to the first planet carrier 410.

One end of the planet wheel 100 is rotatably connected with the first planet carrier 410, the other end of the planet wheel 100 is rotatably connected with the second planet carrier 420, and the planet wheel 100 is meshed with the sun wheel 200. One end of the sun gear 200 is rotatably connected to the first carrier 410, the other end of the sun gear 200 is rotatably connected to the second carrier 420, and the axis of the sun gear 200 coincides with the center lines of the first carrier 410 and the second carrier 420.

The connecting plate 430 is arc-shaped, a connecting plate 430 is arranged between every two planetary gears 100, the connecting plate 430 is uniformly arranged along the circumferential direction of the axis of the central hole, the mounting position of the connecting plate 430 is not higher than that of the planetary carrier assembly 400, the inner gear 300 is sleeved outside the connecting plate 430, and the inner gear 300 is meshed with the planetary gears 100.

Further, in the present application, the carrier close to the power input end is referred to as a first carrier 410, and the carrier far from the power input end is referred to as a second carrier 420.

In one embodiment, the first planet carrier 410 and the second planet carrier 420 are symmetrically fixed to both sides of the connection plate 430 by bolts. The connecting plate 430 is provided with bolt holes, the first planet carrier 410 and the second planet carrier 420 are both provided with through holes through which bolts pass, the bolts pass through from one side of the first planet carrier 410, pass through the first planet carrier 410, the connecting plate 430 and the second planet carrier 420, and then the first planet and the second planet carrier 420 are symmetrically fixed on the connecting plate 430.

As shown in fig. 4 and 5, in an embodiment, the transmission structure further includes an input shaft 500, the connecting shaft 220 is fixedly disposed on an end surface of the sun gear 200, a connecting gear sleeve 600 is disposed on the connecting shaft 220, and the connecting gear sleeve 600 is used for fixedly connecting the input shaft 500 to the connecting shaft 220.

One end of the connecting shaft 220 is fixedly connected with one end face of the sun gear 200, the other end of the connecting shaft 220 is fixedly connected with the input shaft 500 through the connecting gear sleeve 600, and the input shaft 500 rotates to drive the sun gear 200 to rotate.

In one embodiment, at least one first position-limiting strip 610 is fixedly arranged in the connecting gear sleeve 600, a second position-limiting strip 221 abutting against the first position-limiting strip 610 is fixedly arranged on the connecting shaft 220, and a third position-limiting strip 510 abutting against the first position-limiting strip 610 is fixedly arranged on the input shaft 500.

The first limiting strips 610 are uniformly arranged along the axial direction of the connecting gear sleeve 600 at intervals, the length of the first limiting strips 610 is equal to that of the connecting gear sleeve 600, the second limiting strips 221 are uniformly arranged along the axial direction of the connecting shaft 220 at intervals, the length of the second limiting strips 221 is not more than half of that of the connecting gear sleeve 600, the number of the second limiting strips 221 is equal to that of the first limiting strips 610, the number of the third limiting strips 510 is uniformly arranged along the axial direction of the input shaft 500 at intervals, the length of the third limiting strips 510 is not more than half of that of the connecting gear sleeve 600, the number of the third limiting strips 510 is equal to that of the second limiting strips 221, the connecting gear sleeve 600 is sleeved outside the connecting shaft 220, one first limiting strip 610 is inserted between two adjacent second limiting strips 221, the input shaft 500 is inserted into the connecting gear sleeve 600, one third limiting strip 510 is inserted between two adjacent first limiting strips 610, thereby achieving a fixed connection of input shaft 500 with sun gear 200.

In one embodiment, the input shaft 500 is fixedly provided with a retainer ring 520, and the retainer ring 520 is fixedly arranged at one end of the third stopper 510 away from the sun gear 200.

The retainer ring 520 is arranged at one end of the third limiting strip 510, which is far away from the connecting shaft 220, the retainer ring 520 is fixedly connected with the input shaft 500 in an annular manner and is used for limiting the axial movement of the connecting rack, so that one end of the connecting gear sleeve 600 is abutted against the first planet carrier 410, and the other end of the connecting gear sleeve is abutted against the retainer ring 520, thereby preventing the connecting gear sleeve 600 from moving along the axial direction of the input shaft 500.

As shown in fig. 6 and 7, in one embodiment, the transmission structure includes an output shaft 700, a top block 210 is provided on the other end surface of the sun gear 200, a top ball 710 is provided on one side surface of the output shaft 700 close to the sun gear 200, and the top ball 710 abuts against the top block 210.

The top ball 710 is a hemisphere, a groove for installing the top ball 710 is formed in one end, close to the sun gear 200, of the output shaft 700, a groove for installing the top block 210 is formed in one end, away from the input shaft 500, of the sun gear 200, and when the input shaft 500 is installed on the planet carrier assembly frame, the top point of the top ball 710 is abutted to the surface of the top block 210, so that the output shaft 700 rotates more smoothly, and friction between the output shaft 700 and the sun gear 200 is reduced.

As shown in fig. 8, in one embodiment, the second carrier 420 is provided with a first mounting hole 421.

In one embodiment, a mounting plate 720 is provided at one end of the output shaft 700, and a second mounting hole 721 corresponding to the first mounting hole 421 is provided in the mounting plate 720.

The first mounting holes 421 are uniformly arranged along the circumferential direction of the central line of the second planet carrier 420, the mounting plate 720 is fixedly connected to one end of the output shaft 700, the second mounting holes 721 are uniformly arranged along the circumferential direction of the axis of the output shaft 700, the number, size and shape of the second mounting holes 721 are the same as those of the first mounting holes 421, and the output shaft 700 passes through the first mounting holes 421 and the second mounting holes 721 through bolts and then is fixedly connected with the second planet carrier 420.

The transmission steps of the planetary gear speed reduction transmission structure in the application are as follows: an input shaft 500 of a motor is connected with an input shaft 500 in a planetary gear speed reduction transmission structure, and a load is connected with an output shaft 700 in the planetary gear speed reduction transmission structure, wherein an inner gear 300 in the planetary gear speed reduction transmission structure is fixedly connected with a shell 800, the motor is started to drive the input shaft 500 in the planetary gear speed reduction transmission structure to rotate, and further drive a sun gear 200 to rotate, the sun gear 200 is meshed with a planet gear 100, and further drive the planet gear 100 to rotate, the planet gear 100 is meshed with the inner gear 300, and the planet gear 100 is rotatably connected to a planet carrier assembly 400, when the sun gear 200 drives the planet gear 100 to rotate, the planet gear 100 not only conducts self transmission, but also revolves around the sun gear 200, and further drives the planet carrier assembly 400 to rotate, a second planet carrier 420 in the planet carrier assembly 400 is fixedly connected with the output shaft 700.

A first embodiment of a speed reducer disclosed in the present invention is described in detail below with reference to fig. 1 to 14. The embodiment is mainly applied to a speed reducer, the first planet carrier and the second planet carrier are symmetrically fixed on two sides of the connecting plate through bolts, so that two ends of a planet wheel of the speed reducer are supported, and the planet wheel is convenient to mount and replace; the input shaft is fixedly connected with the sun gear through the connecting gear sleeve, so that the sun gear is convenient to disassemble and replace; the output shaft and the sun wheel are abutted through the jacking ball and the jacking block, so that friction is reduced, and the output shaft can rotate more smoothly; the first positioning pin is used for fixing the internal gear and the shell, and the second positioning pin is used for fixing the internal gear and the planet carrier, so that conversion between single-stage speed regulation and two-stage speed regulation is realized.

As shown in fig. 1 to 14, the present embodiment mainly includes a device case 800 described in the first embodiment of the planetary gear reduction transmission structure, and a first positioning pin 810.

As shown in fig. 11, a limiting bar and a first pin hole for allowing the first locating pin 810 to pass through are arranged inside the speed reducer casing 800, wherein the limiting bar is arranged on two sides of the inner gear 300, so as to limit the movement of the inner gear 300 in the axial direction, the first locating pin 810 passes through the casing 800 and abuts against the inner gear 300, the inner gear 300 is fixed with the casing 800, and the inner gear 300 is sleeved outside the planet carrier assembly 400 and is meshed with the planet gear 100.

The planet gears 100 are rotatably connected to the planet carrier assembly 400, the planet carrier assembly 400 comprises a first planet carrier 410, a second planet carrier 420 and a connecting plate 430, the first planet carrier 410 and the second planet carrier 420 are symmetrically arranged on two sides of the connecting plate 430, so that the planet gears 100 can be conveniently installed and replaced, and two ends of the planet gears 100 are supported, and the planet gears 100 are prevented from being broken due to one side stress.

The first planet carrier 410 is triangular, and the intersection point of every two intersecting first planet carriers is provided with an arc chamfer, the center of the first planet carrier 410 is provided with a center hole, and a first bearing is arranged in the center hole and used for mounting the sun gear 200. Through holes are uniformly formed in the first planet carrier 410 along the axis of the central hole in the circumferential direction, second bearings are arranged in the through holes and used for mounting the planet wheels 100, and the number of the through holes is equal to that of the planet wheels 100. The second planet carrier 420 is identical in structure, size and shape to the first planet carrier 410. One end of the planet wheel 100 is rotatably connected with the first planet carrier 410, the other end of the planet wheel 100 is rotatably connected with the second planet carrier 420, and the planet wheel 100 is meshed with the sun wheel 200. One end of the sun gear 200 is rotatably connected to the first carrier 410, the other end of the sun gear 200 is rotatably connected to the second carrier 420, and the axis of the sun gear 200 coincides with the center lines of the first carrier 410 and the second carrier 420. The connecting plate 430 is arc-shaped, a connecting plate 430 is arranged between every two planetary gears 100, the connecting plate 430 is uniformly arranged along the circumferential direction of the axis of the central hole, the mounting position of the connecting plate 430 is not higher than that of the planetary carrier assembly 400, the inner gear 300 is sleeved outside the connecting plate 430, and the inner gear 300 is meshed with the planetary gears 100.

The first positioning pins 810 are uniformly arranged along the circumferential direction of the axis of the inner gear 300 to fix the inner gear 300 and the outer shell 800, so that the speed reducer realizes two-stage speed reduction.

As shown in fig. 14, in one embodiment, the reduction gear further includes a second positioning pin 820, and the second positioning pin 820 passes through the internal gear 300 and abuts against the connection plate 430.

The outer case 800 is further provided with a second pin hole through which a second positioning pin 820 passes through the outer case 800 to fix the internal gear 300 to the connection plate 430 such that the internal gear 300 rotates together with the planet carrier assembly 400.

Further, the number of the second positioning pins 820 is three along the circumferential direction of the axis of the internal gear 300, and the internal gear 300 and the connecting plate 430 are fixed, so that the speed reducer realizes single-stage speed reduction.

In one embodiment, the first planet carrier 410 and the second planet carrier 420 are symmetrically fixed to both sides of the connection plate 430 by bolts.

In one embodiment, the transmission structure further includes an input shaft 500, a connecting shaft 220 is fixedly disposed on an end surface of the sun gear 200, a connecting gear sleeve 600 is disposed on the connecting shaft 220, and the connecting gear sleeve 600 is used for fixedly connecting the input shaft 500 to the connecting shaft 220.

In one embodiment, the transmission structure includes an output shaft 700, a top block 210 is disposed on the other end surface of the sun gear 200, a top ball 710 is disposed on one side surface of the output shaft 700 close to the sun gear 200, and the top ball 710 abuts against the top block 210.

In one embodiment, the second carrier 420 is provided with a first mounting hole 421.

The specific structures of the planet gear 100, the sun gear 200, the inner gear 300, the planet carrier assembly member 400 and other components of this embodiment can refer to the structural arrangement described in the first embodiment of the aforementioned planetary gear speed reduction transmission structure, and are not described again.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A planetary gear reduction transmission structure, comprising: a planet wheel (100), a sun wheel (200), an inner gear (300) and a planet carrier assembly member (400);

the planet carrier assembly member (400) comprises a first planet carrier (410), a second planet carrier (420) and a connecting plate (430), wherein the first planet carrier (410) and the second planet carrier (420) are symmetrically arranged at two sides of the connecting plate (430);

one end of the sun gear (200) is rotationally connected with the first planet carrier (410), the other end of the sun gear (200) is rotationally connected with the second planet carrier (420), and the axis of the sun gear (200) is superposed with the central lines of the first planet carrier (410) and the second planet carrier (420);

one end of the planet wheel (100) is rotationally connected with the first planet carrier (410), the other end of the planet wheel (100) is rotationally connected with the second planet carrier (420), and the planet wheel (100) is meshed with the sun wheel (200);

the inner gear (300) is sleeved on the outer side of the connecting plate (430), and the planet gear (100) is meshed with the inner gear (300).

2. A planetary gear reduction transmission according to claim 1, wherein the first planet carrier (410) and the second planet carrier (420) are symmetrically fixed to both sides of the connecting plate (430) by bolts.

3. A planetary gear reduction transmission according to claim 1, characterized in that the transmission further comprises an input shaft (500), a connecting shaft (220) is fixedly provided on one end face of the sun gear (200), a connecting gear sleeve (600) is provided on the connecting shaft (220), and the connecting gear sleeve (600) is used for fixedly connecting the input shaft (500) to the connecting shaft (220).

4. A planetary gear reduction transmission according to claim 3, wherein at least one first limiting strip (610) is fixedly arranged in the connecting gear sleeve (600), a second limiting strip (221) abutting against the first limiting strip (610) is fixedly arranged on the connecting shaft (220), and a third limiting strip (510) abutting against the first limiting strip (610) is fixedly arranged on the input shaft (500).

5. A planetary gear reduction transmission according to claim 4, wherein the input shaft (500) is fixedly provided with a retainer ring (520), and the retainer ring (520) is fixedly arranged at one end of the third limiting strip (510) far away from the sun gear (200).

6. A planetary gear reduction transmission according to claim 1, wherein the transmission comprises an output shaft (700), a top block (210) is provided on the other end face of the sun gear (200), a top ball (710) is provided on one side face of the output shaft (700) close to the sun gear (200), and the top ball (710) abuts against the top block (210).

7. A planetary gear reduction transmission according to claim 6, characterized in that the second planet carrier (420) is provided with a first mounting hole (421).

8. A planetary gear reduction transmission according to claim 7, wherein an end of the output shaft (700) is provided with a mounting plate (720), and the mounting plate (720) is provided with a second mounting hole (721) corresponding to the first mounting hole (421).

9. A speed reducer, comprising: the planetary gear speed reducing transmission mechanism comprises a shell (800), a planetary gear speed reducing transmission structure and a first positioning pin (810), wherein the first positioning pin (810) penetrates through the shell (800) and is abutted to an inner gear (300);

the planetary gear reduction transmission structure is the planetary gear reduction transmission structure according to any one of claims 1 to 8.

10. A reducer according to claim 9, further comprising a second positioning pin (820), the second positioning pin (820) abutting against a connecting plate (430) through the internal gear (300).