CN216180505U

CN216180505U - L-shaped actuator, mechanical arm and robot

Info

Publication number: CN216180505U
Application number: CN202122406290.8U
Authority: CN
Inventors: 罗程; 刘猛; 方鑫; 黄晓庆; 孔兵
Original assignee: Cloudminds Robotics Co Ltd
Current assignee: Cloudminds Shanghai Robotics Co Ltd
Priority date: 2021-09-30
Filing date: 2021-09-30
Publication date: 2022-04-05
Anticipated expiration: 2031-09-30
Also published as: CN218905391U

Abstract

The embodiment of the utility model relates to the technical field of actuators, and discloses an L-shaped actuator, a mechanical arm and a robot; the L-shaped actuator comprises a driving module and a transmission module, wherein the driving module comprises a motor; the transmission module comprises an output piece and a speed reducing assembly for driving the output piece, and the speed reducing assembly and the motor are arranged side by side at intervals; the L-shaped actuator further comprises a transmission assembly which is in transmission connection between the motor and the speed reduction assembly, and the transmission assembly comprises a main transmission part which is connected with the speed reduction assembly; the transmission module is provided with a central through hole which axially penetrates through the output part, the speed reducing assembly and the main transmission part and has openings at two ends. Compared with the prior art, the L-shaped actuator provided by the embodiment of the utility model has the advantages that the axial length is reduced by arranging the speed reducing assembly and the motor at intervals side by side, and the L-shaped actuator is compact and small.

Description

L-shaped actuator, mechanical arm and robot

Technical Field

The embodiment of the utility model relates to the technical field of actuators, in particular to an L-shaped actuator, a mechanical arm and a robot.

Background

With the continuous development of intelligent robot technology, robots are more and more extensive in scoring fields, and in some fields, the robots are required to complete more actions, so that the robots are required to have higher freedom degrees, such as industrial robots, medical robots, bionic robots and the like.

In the existing actuator, a motor and a speed reducing mechanism are generally arranged in an axial direction; however, this axial arrangement often results in a large axial dimension that is inconvenient to install at certain joint locations in the robot.

SUMMERY OF THE UTILITY MODEL

An object of an embodiment of the present invention is to provide an L-shaped actuator which is compact.

In order to solve the above technical problem, an embodiment of the present invention provides an L-shaped actuator, including a driving module and a transmission module, where the driving module includes a motor; the transmission module comprises an output piece and a speed reducing assembly for driving the output piece, and the speed reducing assembly and the motor are arranged side by side at intervals; the L-shaped actuator further comprises a transmission assembly which is in transmission connection between the motor and the speed reduction assembly, and the transmission assembly comprises a main transmission part which is connected with the speed reduction assembly; the transmission module is provided with a central through hole which axially penetrates through the output part, the speed reducing assembly and the main transmission part and has openings at two ends.

In addition, the driving module comprises a driving shell, the transmission module is installed on the driving shell, a first wire guide groove is formed in the bottom of the driving shell, and the first wire guide groove is communicated with the central through hole.

In addition, the driving shell comprises a motor mounting main body and a driving bottom cover mounted at the bottom of the motor mounting main body, the first wire groove is arranged on the driving bottom cover, and the motor is mounted in the motor mounting main body; the motor mounting main body is provided with a second wire groove communicated with the first wire groove, and the driving module is provided with a wire connecting terminal which is exposed in the second wire groove.

In addition, the number of the second wire grooves is multiple, and each second wire groove vertically extends along the outer wall of the motor installation main body; the first wire groove comprises transverse parts and longitudinal parts which are arranged in a staggered and communicated manner, wherein one end of each transverse part is communicated with the central through hole, and the other end of each transverse part is communicated with the lower end of one of the second wire grooves; and two ends of the longitudinal part are respectively communicated with the lower end of one second wire groove.

In addition, the transmission module further comprises a transmission shaft with a hollow inner part, the central through hole is formed in the transmission shaft, the transmission shaft penetrates through the output part and the speed reducing assembly, and one end of the transmission shaft is fixed with the output part.

In addition, the transmission module is including still locating the transmission shaft is worn out the transmission shaft encoder of the outer one end of main drive spare, the transmission shaft encoder include first magnet and with the first chip that first magnet is relative, wherein first magnet by the transmission shaft is driven to rotate.

In addition, the driving module comprises a driving shell, the transmission module is installed on the driving shell, and a first counting gear is fixed on the periphery of the end part of the transmission shaft after penetrating through the main transmission part; a second counting gear meshed with the first counting gear is mounted on the driving shell; the first magnet is arranged at the center of the second counting gear, and the first chip is arranged on the driving shell.

Additionally, the motor includes a motor shaft; the driving module further comprises a band-type brake and a band-type brake locking piece, the band-type brake locking piece is circumferentially positioned and connected with the motor shaft, and the rotation of the motor shaft is limited through the effect of the band-type brake on the band-type brake locking piece.

In addition, the driving module further comprises a driving plate and a motor shaft encoder, wherein the motor shaft encoder comprises a second magnet fixed at the tail end of the motor shaft and a second chip fixed on the driving plate and opposite to the second magnet.

In addition, the main transmission part comprises a main gear and a primary sun gear coaxially fixed with the main gear, and the main gear is in transmission connection with the motor; the reduction assembly includes a planetary gear assembly with which the primary sun gear meshes.

In addition, the main transmission part further comprises a positioning ring platform arranged between the main gear and the primary sun gear, and the transmission module further comprises a first bearing sleeved on the positioning ring platform.

In addition, the transmission module further comprises a ring gear body in which the planetary gear assembly is mounted; the planetary gear assembly comprises a middle planet carrier and a primary planetary gear pivoted on one side of the middle planet carrier; the primary planetary gear is meshed with the primary sun gear, an inner gear ring is arranged on the inner wall of the gear ring main body, and the primary planetary gear is meshed with the inner gear ring; the middle planet carrier is in transmission connection with the output part.

In addition, the planetary gear assembly further comprises a secondary sun gear fixed to the other side of the middle planet carrier and a secondary planet gear pivoted on the output member, the secondary planet gear is meshed with the secondary sun gear, and the secondary planet gear is meshed with the inner gear ring.

In addition, the second-stage sun gear is sleeved with a bearing mounting sleeve, and the transmission module further comprises a second bearing arranged between the outer wall of the output part and the gear ring main body and a third bearing arranged between the inner wall of the output part and the bearing mounting sleeve.

In addition, the main transmission comprises a main gear; the transmission assembly comprises a driving gear installed on the motor and an intermediate gear meshed with the driving gear, and the intermediate gear is meshed with the main gear.

The utility model also provides a mechanical arm which comprises the L-shaped actuator.

The utility model also provides a robot which comprises the mechanical arm.

Compared with the prior art, the L-shaped actuator provided by the embodiment of the utility model has the advantages that the axial length is reduced by arranging the speed reducing assembly and the motor at intervals side by side, and the L-shaped actuator is compact and small. More importantly, in this L type executor, through the central through-hole that runs through output spare, speed reduction subassembly and main drive spare at transmission module setting, can pass the wire from central through-hole and stretch out at output spare terminal surface when using executor or many executor to establish ties, the wire can not appear entangling, stranded conductor, damaged condition when the electricity output spare rotates on the executor like this, has solved the problem that exists when current executor walks the line from the outside.

Drawings

One or more embodiments are illustrated by way of example in the accompanying drawings, which correspond to the figures in which like reference numerals refer to similar elements and which are not to scale unless otherwise specified.

FIG. 1 is a perspective view of an L-shaped actuator according to an embodiment of the present invention;

FIG. 2 is a top view of the L-shaped actuator of FIG. 1;

FIG. 3 is a cross-sectional view of the L-shaped actuator of FIG. 2 taken along line A-A;

FIG. 4 is a schematic perspective view of the L-shaped actuator of FIG. 1 at another angle, in which the first wire cover plate and the second wire cover plate are hidden to show the first wire slot and the second wire slot;

FIG. 5 is an exploded isometric view of another angle of the L-shaped actuator of FIG. 1;

FIG. 6 is an exploded perspective view of a transmission module of the L-shaped actuator of FIG. 5;

FIG. 7 is a partially assembled schematic view of the L-shaped actuator of FIG. 4 shown at another angle with the drive housing hidden.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, it will be appreciated by those of ordinary skill in the art that numerous technical details are set forth in order to provide a better understanding of the present application in various embodiments of the present invention. However, the technical solution claimed in the present application can be implemented without these technical details and various changes and modifications based on the following embodiments.

The utility model relates to an L-shaped actuator, which is characterized by comprising a driving module and a transmission module, wherein the driving module comprises a vertically arranged motor; the transmission module comprises an output piece and a speed reducing assembly, wherein the output piece rotates around a vertical axis, the speed reducing assembly drives the output piece, and the speed reducing assembly and the motor are arranged side by side at intervals; the L-shaped actuator further comprises a transmission assembly which is in transmission connection between the motor and the speed reduction assembly, and the transmission assembly comprises a main transmission part which is connected with the speed reduction assembly; the transmission module is provided with a central through hole which axially penetrates through the output part, the speed reducing assembly and the main transmission part and has openings at two ends. It should be noted that the "L" of the L-shaped actuator is not intended to limit the appearance of the actuator to an L shape, and means that the direction of power transmission between the driving module and the transmission module and the axial direction of the module itself are distributed in an L shape. Compared with the prior art, the L-shaped actuator provided by the embodiment of the utility model has the advantages that the axial length is reduced by arranging the speed reducing assembly and the motor at intervals side by side, and the L-shaped actuator is compact and small. In addition, the transmission module is provided with a central through hole for a lead to pass through, so that the problem of winding or damage of the lead is avoided. The utility model also protects a mechanical arm and a robot, wherein the mechanical arm comprises the L-shaped actuator; the robot comprises the mechanical arm.

The implementation details of the L-shaped actuator of the present embodiment are described in detail below, and the following description is provided only for the sake of understanding and is not necessary for implementing the present embodiment.

Referring to fig. 1 to 7, an L-shaped actuator according to an embodiment of the present invention is used in a robot, especially an intelligent robot such as an industrial robot, a medical robot, a bionic robot, and the like. The L-shaped actuator is an electric actuator. The L-shaped actuator includes a transmission module 10 and a driving module 60. The driving module 60 includes a vertically disposed motor 63; the transmission module 10 comprises an output member 80 rotating around a vertical axis and a speed reducing assembly driving the output member 80, wherein the speed reducing assembly and the motor 63 are arranged side by side at intervals; the L-shaped actuator further comprises a transmission assembly 70 which is in transmission connection between the motor 63 and the speed reducing assembly; the transmission assembly 70 comprises a main transmission member 30 connected to the reduction assembly; the transmission module 10 has a central through hole 52 axially passing through the output member 80, the reduction assembly and the main transmission member 30 and having both ends open. In the present embodiment, the central through hole 52 is used for the wire connecting the external actuator and the internal wire terminal interface to pass through, so as to avoid the problem of wire winding or breakage.

Referring to fig. 1 to 5, the driving module 60 includes a driving housing (not shown), the transmission module 10 is mounted on the driving housing, and a first wire guiding groove 610 is formed at the bottom of the driving housing, and the first wire guiding groove 610 is communicated with the central through hole 52. Specifically, the drive housing includes a motor mounting body 62 and a drive bottom cover 61 mounted on the motor mounting body 62, the first wire guide 610 is disposed on the drive bottom cover 61, and the motor 63 is mounted in the motor mounting body 62; the motor mounting body 62 is provided with a second wire guide 620 communicated with the first wire guide 610. Further, the driving bottom cover 61 is mounted with a first wire cover plate 611 to cover the first wire groove 610; the driving module 60 has wire connection terminals exposed in the second wire groove 620. The motor mounting body 62 is provided with a second wire cover 621 to cover the second wire groove 620 correspondingly.

In this embodiment, the number of the second wire grooves 620 is plural, and each second wire groove 620 extends vertically along the outer wall of the motor mounting body 62; the first wire groove 610 includes a transverse portion and a longitudinal portion which are alternately communicated, wherein one end of the transverse portion is communicated with the central through hole 52, and the other end is communicated with the lower end of one of the second wire grooves 620; both ends of the longitudinal portion communicate with the lower end of one second wire groove 620, respectively. Specifically, the first wire groove 610 is disposed in a cross shape.

The drive module 60 also includes a drive plate 68. In other words, the first wire guide 610 of the driving bottom cover 61 communicates with the center through hole 52 of the driving shaft 50 and the second wire guide 620 of the motor mounting body 62, respectively. Specifically, the second wire groove 620 is communicated to the wire connection terminals of the motor 63 and the drive plate 68, respectively; i.e., the second wire guide 620, for receiving wires for connecting the motor 63 and the driving plate 68, respectively. The drive module 60 further includes a motor tail cover 66, and the motor tail cover 66 is mounted to the bottom of the motor mounting body 62 and protects the drive plate 68.

The motor 63 includes a motor shaft 630 (as shown in fig. 3), in this embodiment, the motor 63 is an external rotor motor and includes a rotor cover 631 covering the stator, the middle of the rotor cover 631 has a shaft portion extending into the base of the stator, and the motor shaft 630 is fixed to the end of the shaft portion so as to rotate synchronously with the rotor cover 631; the drive module 60 also includes a motor shaft encoder that includes a second magnet 69 fixed to the end of the motor shaft 630 and a second chip fixed to the drive plate 68 opposite the second magnet 69 to record the number of rotations of the motor shaft 630. Specifically, the second chip on the drive plate 68 records the number of revolutions of the motor 63 by recording the number of times the second magnet 69 is rotated to cause the magnetic field to change.

The driving module 60 further comprises a band-type brake 65 and a band-type brake locking piece 67 which are installed in the motor installation body 61, the band-type brake locking piece 67 is circumferentially positioned and connected with the motor shaft 620, and the rotation of the motor shaft 620 is limited by the effect of the band-type brake 65 on the band-type brake locking piece 67. Specifically, after the motor shaft 620 passes through the motor 62 and the band-type brake 65, the tail part of the shaft body is matched with the band-type brake locking piece 67, and the tail part of the shaft body of the motor shaft 620 is axially limited in the band-type brake 65 through the snap spring; when the brake 65 is powered on, the motor shaft 620 can rotate freely, and when the brake 65 is powered off, the brake 65 limits the rotation of the brake locking piece 67 so as to limit the rotation of the motor shaft 620.

The transmission assembly 70 further includes a driving gear 71 mounted on the motor 63 and an intermediate gear 72 engaged with the driving gear 71, the intermediate gear 73 being connected to the main transmission member 30.

The main transmission member 30 comprises a main gear 31 and a primary sun gear 32 coaxially fixed with the main gear 31, wherein the main gear 31 is in transmission connection with the motor 63; specifically, the main gear 31 meshes with the intermediate gear 73. The reduction assembly includes a planetary gear assembly 40, with the primary sun gear 32 meshing with the planetary gear assembly 40. The main transmission 30 further comprises a positioning collar (not shown) arranged between the main gear 31 and the primary sun gear 32, and the transmission module 10 further comprises a first bearing 11 arranged on the positioning collar.

Referring to fig. 6 and 7, the transmission module 10 further includes a ring gear main body 20; a planetary gear assembly 40 is mounted in the ring gear body 20. The gear ring main body 20 is a hollow cylinder, and an inner gear ring is disposed on an inner wall of the gear ring main body 20 to be correspondingly engaged with the planetary gear assembly 40.

Specifically, the planetary gear assembly 40 includes a middle planet carrier 41, a primary planetary gear 42 pivoted to one side of the middle planet carrier 41, and a secondary sun gear 43 fixedly connected to the other side of the middle planet carrier 41; the primary planetary gear 41 meshes with the primary sun gear 32. The inner wall of the gear ring main body 20 is provided with an inner gear ring, and the primary planet gear 42 is meshed with the inner gear ring; the intermediate carrier 41 is drivingly connected to the output member 80.

Further, the number of the primary planet gears 42 is five, and the primary planet gears 42 are circumferentially distributed and are respectively pivoted on the middle planet carrier 41, and each primary planet gear 42 is meshed with the primary sun gear 32 and simultaneously meshed with the inner gear ring of the gear ring main body 20, so that the stable operation of the primary planet gear 42 is maintained. The primary planet gears 42 surround and mesh around the primary sun gear 32; when the motor 63 rotates and the primary transmission member 30 is rotated by the transmission assembly 70, the primary sun gear 32 rotates and drives the primary planet gears 42 to rotate by meshing, and the primary planet gears 42 rotate and move along the inner ring gear of the ring gear body 20 due to meshing with the inner ring gear of the ring gear body 20, i.e., revolve around the primary sun gear 32, and the revolution drives the intermediate planet carrier 41 to rotate, thereby driving the secondary sun gear 43 to rotate.

The planetary gear assembly 40 also includes a secondary planetary gear 45 pivotally connected to the output member 80. The secondary planet gears 45 are meshed with the secondary sun gear 43, and the secondary planet gears 45 are meshed with the inner gear ring. In the present embodiment, the number of the secondary planetary gears 45 is five, and the secondary planetary gears 45 are circumferentially distributed and respectively pivoted on the output member 80. The secondary planet gears 45 surround and mesh around the secondary sun gear 43. When the secondary sun gear 43 rotates, the output member 80 is driven to rotate by the secondary planet gears 45. In the present embodiment, each secondary planetary gear 45 meshes with the secondary sun gear 43 and also meshes with the ring gear of the ring gear body 20.

When the motor 63 rotates to drive the transmission assembly 70, the main transmission member 30 and the intermediate planet carrier 41 to rotate, the primary sun gear 32 rotates and drives the secondary planet gears 45 to rotate by utilizing the meshing relationship, and the secondary planet gears 45 rotate and move along the inner gear ring of the gear ring body 20 due to the meshing relationship with the inner gear ring of the gear ring body 20, namely, revolve around the secondary sun gear 43, and the revolution drives the output member 43 to rotate, thereby driving the output member 43 and the transmission shaft 50 to rotate.

Further, a bearing mounting sleeve is sleeved on the secondary sun gear 43, and the transmission module 10 further includes a second bearing 12 disposed between the outer wall of the output member 80 and the gear ring main body 20, and a third bearing 13 disposed between the inner wall of the output member 80 and the bearing mounting sleeve. By providing the double bearing structure on the inner and outer walls of the output member 80, the axial play of the output member 80 can be reduced.

The drive shaft 50 is fixedly connected to the output member 80. Specifically, a fixed disk 51 extends radially outward from the peripheral surface of the end of the transmission shaft 50 close to the second mounting end 22, and the fixed disk 51 is fixed with the output member 80 by means of clamping or screwing. The transmission shaft 50 penetrates through the main transmission member 30 and the planetary gear assembly 40; the position of the central through hole 52 of the transmission shaft 50 close to the main transmission member 30 is communicated with the first wire groove 610, and the position of the central through hole 52 close to one end far away from the main transmission member 30 is used for connecting with other actuators, so that the problem that wires are connected from the outside and are wound or damaged is avoided.

Referring to fig. 7, a first counter gear 93 is fixed to the outer periphery of the end of the transmission shaft 50 passing through the main transmission member 30; a second counter gear 94 engaged with the first counter gear 93 is mounted on the driving housing; the transmission module 10 further includes a transmission shaft encoder, which includes a first magnet 95 installed at the center of the second counter gear 94 and a first chip 96 installed on the driving housing, and detects the number of rotations of the first magnet 95 of the second counter gear 94 through the first chip 96, thereby detecting the number of rotations of the transmission shaft 50. Since the transmission shaft 50 has a hollow structure and the inner center through hole 52 is used for routing, it is difficult to directly dispose the first magnet 95 on the end surface of the transmission shaft 50, and the rotation of the transmission shaft 50 is transmitted to the first magnet 95 by offsetting the first magnet 95 through two counter gears. Of course, this arrangement is not exclusive, and the magnetic member may be made into a magnetic ring and directly sleeved on the peripheral surface of the end of the transmission shaft 50, and the first chip 96 is staggered from the opening of the transmission shaft 50 to be opposite to the portion of the magnetic ring.

According to the L-shaped actuator, the speed reducing assembly and the motor 63 are arranged side by side at intervals, so that the axial length is reduced, and the L-shaped actuator is compact and small. In addition, the transmission module 10 is provided with a central through hole 52 for the lead to pass through, thereby avoiding the problem of lead winding or breakage.

The driving gear 71 of the utility model is decelerated by the upper stages through the transmission with the intermediate gear 72, the main transmission member 30, the intermediate planet carrier 41 and the output member 80, so that the reduction ratio of the driving gear 71 finally transmitted to the transmission shaft 50 is 80; therefore, the large deceleration is realized, and the requirement of flexible execution is met.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples for carrying out the utility model, and that various changes in form and details may be made therein without departing from the spirit and scope of the utility model in practice.

Claims

1. An L-shaped actuator is characterized by comprising a driving module and a transmission module, wherein the driving module comprises a motor; the transmission module comprises an output piece and a speed reducing assembly for driving the output piece, and the speed reducing assembly and the motor are arranged side by side at intervals; the L-shaped actuator further comprises a transmission assembly which is in transmission connection between the motor and the speed reduction assembly, and the transmission assembly comprises a main transmission part which is connected with the speed reduction assembly; the transmission module is provided with a central through hole which axially penetrates through the output part, the speed reducing assembly and the main transmission part and has openings at two ends.

2. The L-shaped actuator according to claim 1, wherein the driving module comprises a driving shell, the transmission module is mounted on the driving shell, and a first wire guide groove is formed in the bottom of the driving shell and communicated with the central through hole.

3. The L-shaped actuator according to claim 2, wherein the drive housing comprises a motor mounting body and a drive bottom cover mounted at the bottom of the motor mounting body, the first wire guide groove is provided on the drive bottom cover, and the motor is mounted in the motor mounting body; the motor mounting main body is provided with a second wire groove communicated with the first wire groove, and the driving module is provided with a wire connecting terminal which is exposed in the second wire groove.

4. The L-shaped actuator according to claim 3, wherein the number of the second wire grooves is multiple, and each second wire groove vertically extends along the outer wall of the motor mounting main body; the first wire groove comprises transverse parts and longitudinal parts which are arranged in a staggered and communicated manner, wherein one end of each transverse part is communicated with the central through hole, and the other end of each transverse part is communicated with the lower end of one of the second wire grooves; and two ends of the longitudinal part are respectively communicated with the lower end of one second wire groove.

5. The L-shaped actuator according to claim 1, wherein the transmission module further comprises a transmission shaft with a hollow interior, the central through hole is formed in the transmission shaft, the transmission shaft penetrates through the output member and the speed reduction assembly, and one end of the transmission shaft is fixed with the output member.

6. The L-shaped actuator according to claim 5, wherein the transmission module further comprises a transmission shaft encoder disposed at an end of the transmission shaft extending out of the main transmission member, the transmission shaft encoder comprises a first magnet and a first chip opposite to the first magnet, and the first magnet is driven by the transmission shaft to rotate.

7. The L-shaped actuator according to claim 6, wherein the driving module comprises a driving shell, the transmission module is installed on the driving shell, and a first counting gear is fixed on the periphery of the end part of the transmission shaft after the transmission shaft passes through the main transmission piece; a second counting gear meshed with the first counting gear is mounted on the driving shell; the first magnet is arranged at the center of the second counting gear, and the first chip is arranged on the driving shell.

8. The L-shaped actuator according to claim 1, wherein the motor comprises a motor shaft; the driving module further comprises a band-type brake and a band-type brake locking piece, the band-type brake locking piece is circumferentially positioned and connected with the motor shaft, and the rotation of the motor shaft is limited through the effect of the band-type brake on the band-type brake locking piece.

9. The L-shaped actuator according to claim 8 wherein said drive module further comprises a drive plate and a motor shaft encoder, said motor shaft encoder including a second magnet fixed to an end of said motor shaft and a second chip fixed to said drive plate and opposing said second magnet.

10. An L-shaped actuator according to claim 1, wherein the main transmission member comprises a main gear and a primary sun gear coaxially fixed with the main gear, and the main gear is in transmission connection with the motor; the reduction assembly includes a planetary gear assembly with which the primary sun gear meshes.

11. An L-shaped actuator according to claim 10 wherein the main transmission member further comprises a positioning ring disposed between the main gear and the primary sun gear, and the transmission module further comprises a first bearing disposed on the positioning ring.

12. The L-shaped actuator according to claim 10 wherein said transmission module further comprises a ring gear body, said planetary gear assembly being mounted in said ring gear body; the planetary gear assembly comprises a middle planet carrier and a primary planetary gear pivoted on one side of the middle planet carrier; the primary planetary gear is meshed with the primary sun gear, an inner gear ring is arranged on the inner wall of the gear ring main body, and the primary planetary gear is meshed with the inner gear ring; the middle planet carrier is in transmission connection with the output part.

13. An L-shaped actuator according to claim 12 wherein the planetary gear assembly further comprises a secondary sun gear fixed to the other side of the intermediate carrier and a secondary planet gear journalled on the output member, the secondary planet gear being in mesh with the secondary sun gear and the secondary planet gear being in mesh with the annulus gear.

14. An L-shaped actuator according to claim 13 wherein the secondary sun gear is sleeved with a bearing mounting sleeve, the transmission module further comprising a second bearing disposed between the outer wall of the output member and the ring gear body, and a third bearing disposed between the inner wall of the output member and the bearing mounting sleeve.

15. An L-shaped actuator according to claim 1, wherein the main transmission comprises a main gear; the transmission assembly comprises a driving gear installed on the motor and an intermediate gear meshed with the driving gear, and the intermediate gear is meshed with the main gear.

16. A robot arm comprising an L-shaped actuator according to any of claims 1 to 15.

17. A robot comprising an L-shaped actuator according to any of claims 1-15.