CN115929869A

CN115929869A - Light-duty reduction gear and anthropomorphic robot

Info

Publication number: CN115929869A
Application number: CN202211614617.3A
Authority: CN
Inventors: 金正已; 胡牧原; 张一雨
Original assignee: Rouhao Precision Technology Suzhou Co ltd
Current assignee: Rouhao Precision Technology Suzhou Co ltd
Priority date: 2022-12-15
Filing date: 2022-12-15
Publication date: 2023-04-07
Also published as: CN116717575A; WO2024124996A1

Abstract

The invention discloses a light speed reducer and a humanoid robot. This light-duty reduction gear includes: a ring gear capable of elastic deformation, the ring gear being disposed in the first housing so as to mesh therewith; the eccentric shaft is used for driving the first harmonic rigid gear and the second harmonic rigid gear to rotate, a hollow cavity is formed in the eccentric shaft, and the hollow cavity penetrates through the eccentric shaft along the axial direction and is provided with two open ends; the central gear is used for driving the eccentric shaft to rotate; the flexible shaft connecting piece is used for being connected with an output shaft of the motor through a flexible shaft, the flexible shaft connecting piece is meshed with the central gear, and the flexible shaft connecting piece is provided with a flexible shaft interface into which the end part of the flexible shaft can be inserted; the first harmonic rigid gear and the second harmonic rigid gear are both provided with second external teeth capable of being meshed with the gear ring; the output flange is rotationally arranged in the first shell and is connected with the first harmonic rigid gear and the second harmonic rigid gear. The light speed reducer has compact structure and larger design freedom.

Description

Light speed reducer and humanoid robot

Technical Field

The invention relates to a light speed reducer and a humanoid robot with the same.

Background

The speed reducer is a power transmission mechanism, and the purposes of reducing output rotating speed and increasing output torque are achieved by utilizing a gear train. The mainstream robot joint precision speed reducer in the current market has two types: one is an RV reducer and the other is a harmonic reducer. The second-stage cycloidal pin gear small tooth difference transmission in the RV reducer is a K-H-V type gear transmission mechanism which is composed of a 1-tooth difference internal gear pair consisting of a short-spoke epicycloidal gear and a pin gear, an eccentric element (a planet carrier) and an output mechanism. The harmonic gear transmission mechanism is an abnormal planetary gear transmission machine consisting of a wave generator, a flexible gear and a rigid gear, wherein the flexible gear and the rigid gear have small tooth difference, and the flexible gear and the rigid gear are elastically deformed to play a role of an abnormal planetary gear in the mechanism. However, the RV reducer has the problems of transmission error caused by abrasion in the transmission process, inconvenience in output precision control and high processing difficulty; and the transmission error and precision of the harmonic gear transmission mechanism need to be further improved. In addition, the two transmission mechanisms have the problems of complex speed ratio adjustment or small adjustable speed ratio range, are more limited when being assembled into a robot, and have small design freedom.

Disclosure of Invention

In view of the above problems, it is an object of the present invention to provide a lightweight speed reducer which is compact and has a large degree of freedom in design. Another object of the present invention is to provide a humanoid robot which can easily realize multi-speed ratio transmission, has high torsional rigidity and high precision, and has a large degree of freedom in mounting a motor.

The invention provides a light speed reducer, which comprises a first shell and an output flange, wherein first inner teeth are arranged on the first shell;

the lightweight speed reducer further includes:

a ring gear that is elastically deformable, the ring gear having first external teeth and second internal teeth, the ring gear being disposed in the first housing and the first external teeth and the first internal teeth being meshed;

a first harmonic rigid gear;

a second harmonic rigid gear eccentrically disposed with respect to the first harmonic rigid gear;

the eccentric shaft is used for driving the first harmonic rigid gear and the second harmonic rigid gear to rotate, a hollow cavity is formed in the eccentric shaft, and the hollow cavity penetrates through the eccentric shaft along the axial direction and is provided with two open ends;

the central gear is used for driving the eccentric shaft to rotate;

the flexible shaft connecting piece is connected with an output shaft of the motor through a flexible shaft, is meshed with the central gear, and is provided with a flexible shaft interface into which the end part of the flexible shaft can be inserted;

wherein the first harmonic rigid gear and the second harmonic rigid gear each have second external teeth capable of intermeshing with the second internal teeth, the first harmonic rigid gear having a first mesh with the ring gear, the second harmonic rigid gear having a second mesh with the ring gear, the first mesh and the second mesh being spaced apart in a circumferential direction of the ring gear;

the eccentric shaft is provided with a first shaft section, a second shaft section and an input shaft section, the first shaft section, the second shaft section and the input shaft section are arranged eccentrically, the first harmonic rigid gear is arranged on the first shaft section, the second harmonic rigid gear is arranged on the second shaft section, and the central gear is arranged on the input shaft section;

the output flange is rotatably arranged in the first shell, and the output flange is connected with the first harmonic rigid gear and the second harmonic rigid gear.

Preferably, the light speed reducer further comprises a second shell, the second shell is fixedly connected with the first shell, the input shaft section penetrates through the second shell, a bearing is arranged between the input shaft section and the second shell, and the flexible shaft connecting piece is rotatably arranged on the second shell.

More preferably, the flexible shaft connector is inserted into the second housing, a bearing is arranged between the flexible shaft connector and the second housing, and the flexible shaft interface is arranged at the end of the flexible shaft connector and exposed from the second housing.

Preferably, the rotation axis of the flexible shaft connector is parallel to and does not coincide with the axis of the input shaft section, and the flexible shaft connector is located on the outer side of the input shaft section.

Preferably, the flexible shaft interface is provided with an interface slot, and the interface slot is non-circular (such as square), so that the flexible shaft can drive the flexible shaft connecting piece to rotate.

Preferably, the axis of the input shaft segment is taken as the first axis, the first shaft segment and the second shaft segment are respectively eccentrically arranged relative to the first axis, and the first shaft segment and the second shaft segment are eccentrically arranged relative to each other. The axial lead of the first shaft section is marked as a second axial lead, the axial lead of the second shaft section is a third axial lead, and the first axial lead, the second axial lead and the third axial lead are parallel to each other. Further, the second axis and the third axis are respectively located on two opposite sides of the first axis. Furthermore, the first axis, the second axis and the third axis are located in the same plane. Specifically, the second axis and the third axis are respectively located on two opposite sides of the first axis, the second axis and the first axis have a distance d1, and the third axis and the first axis have a distance d2. Advantageously, the spacing d1 is equal to the spacing d2.

In a preferred embodiment, the second axis (i.e. the rotation axis of the first harmonic rigid gear) and the third axis (i.e. the rotation axis of the first harmonic rigid gear) are respectively located at the upper and lower sides of the first axis, and the distance d1 between the second axis and the first axis is equal to the distance d2 between the third axis and the first axis. Correspondingly, the first harmonic rigid gear is meshed with the upper side of the gear ring at the upper side, and the second harmonic rigid gear is meshed with the lower side of the gear ring at the lower side, namely the first meshing part and the second meshing part are respectively positioned at the upper side and the lower side of the gear ring. The whole gear ring is in a ring shape initially; in operation, the upper and lower side portions of the ring gear are respectively pressed outward, and deformed slightly outward in the up-down direction, and the left and right side portions are deformed inward.

Preferably, the number of second external teeth of the first harmonic rigid gear or the second harmonic rigid gear is smaller than the number of second internal teeth of the ring gear.

Preferably, the sun gear is tightly fitted over the input shaft section.

More preferably, the sun gear is heat treated and then sleeved on the input shaft section.

Preferably, the lightweight speed reducer further comprises at least two needle roller bearings, and the two needle roller bearings are arranged on the inner wall of the hollow cavity at intervals.

Preferably, a bearing is arranged between the first harmonic rigid gear and the first shaft section, and a bearing is arranged between the second harmonic rigid gear and the second shaft section.

Preferably, the first engagement portion and the second engagement portion are located on opposite sides of the ring gear, respectively. The gear ring is a thin-wall elastic gear ring and can generate slight elastic deformation.

Preferably, the eccentric shaft further has a third shaft section, the output flange is sleeved on the third shaft section, and a bearing is arranged between the output flange and the third shaft section; a bearing is arranged between the output flange and the first shell.

Preferably, the light speed reducer further comprises a motor end flange, the motor end flange and the output flange are oppositely arranged and connected with each other, and the first harmonic rigid gear and the second harmonic rigid gear are arranged between the motor end flange and the output flange.

More preferably, the motor end flange is rotatably disposed in the first housing with a bearing disposed therebetween, the eccentric shaft further has a fourth shaft section, and the motor end flange is sleeved on the fourth shaft section with a bearing disposed therebetween.

Further, the first harmonic rigid gear and the second harmonic rigid gear are respectively provided with a through hole, the output flange is connected with the motor end flange through a bolt, the bolt penetrates through the through holes of the first harmonic rigid gear and the second harmonic rigid gear, and the aperture of the through hole is larger than the outer diameter of the bolt.

Preferably, a sealing ring is further arranged between the output flange and the first housing. And a sealing ring is arranged between the second shell and the input shaft section. And a sealing ring is arranged between the second shell and the flexible shaft connecting piece.

The invention provides a humanoid robot, which comprises an elbow joint or a wrist joint, wherein the elbow joint or the wrist joint adopts the light speed reducer; the humanoid robot further comprises a motor, the motor is connected with a flexible shaft connecting piece of the light speed reducer through a flexible shaft, and the motor is arranged at the trunk part of the robot.

Compared with the prior art, the invention has the following advantages by adopting the scheme:

the light speed reducer has the characteristics of light weight and compact structure, is convenient to assemble, particularly has convenient and concise steps of assembling into an industrial robot, is convenient to wire, and effectively reduces the risk of scraping or abrasion of a cable. Meanwhile, in the gear meshing process, the flexible deformation of the gear ring is controlled by the meshing of the external teeth of the gear ring and the internal teeth of the first shell, and in the controlled deformation state, the internal teeth of the elastic gear ring and the eccentric gear have a larger meshing containing angle, so that the purpose of high torsional rigidity is achieved; multiple speed ratios under the same outer envelope size can be realized by adjusting the number of pairs of teeth of the central gear; the light speed reducer has the characteristics of high precision and high torsional rigidity, can be suitable for the working conditions of various speed ratios, and has larger design freedom.

The humanoid robot has the characteristics of light weight and compact structure of the light speed reducer adopted by the elbow joint or the wrist joint, high precision and high torsional rigidity, can install the motor at a proper position (such as a trunk part with larger space) of the humanoid robot, and has better motor installation freedom.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

Fig. 1 is a front view of a lightweight speed reducer according to an embodiment of the present invention, in which a second housing and a flexible shaft connector are not shown.

Fig. 2 is a left side view of the lightweight speed reducer of fig. 1, wherein the second housing and the flexible shaft connection are not shown.

Fig. 3 is a right side view of the lightweight speed reducer of fig. 1, wherein the second housing and the flexible shaft connection are not shown.

Fig. 4 isbase:Sub>A rotational sectional view taken along the linebase:Sub>A-base:Sub>A in fig. 3.

FIG. 5 is a cross-sectional view of a lightweight speed reducer including a second housing and a flexible shaft connection according to an embodiment of the present invention.

Fig. 6 is a partially enlarged view of fig. 5 at B.

Fig. 7 is a partial enlarged view at C in fig. 5.

Fig. 8 is a partial enlarged view of fig. 5 at D.

Fig. 9 is a structural view of an output flange according to an embodiment of the present invention.

Fig. 10 is a left side view of the output flange of fig. 9.

Fig. 11 is a rotary sectional view taken along line E-E in fig. 10.

Fig. 12 is a structural view of a motor end flange according to an embodiment of the present invention.

Fig. 13 is a left side view of the motor end flange of fig. 12.

Fig. 14 is a rotational sectional view in the direction F-F in fig. 13.

FIG. 15 is a left side view of a first harmonic rigid gear in accordance with an embodiment of the present invention.

Fig. 16 is a rotary sectional view taken along line G-G in fig. 14.

Reference numerals:

1. a first housing; 11. a first internal tooth;

2. a ring gear; 21. a first outer tooth; 22. a second internal tooth;

3a, a first harmonic rigid gear; 3b, a second harmonic rigid gear; 31. a second external tooth; 32. a through hole; 33. a first screw hole;

4. an eccentric shaft; 40. a hollow cavity; 41. a first shaft section; 42. a second shaft section; 43. a third shaft section; 44. a fourth shaft section; 45. an input shaft section; 46. a needle bearing;

5. an output flange; 50. an output end connector; 51. an end cap; 52. a first bolt hole; 53. a stud;

6. a sun gear;

7. a motor end flange; 71. a second bolt hole; 72. a second screw hole;

8. a bearing;

9. a seal ring;

101. a bolt; 102. a screw; 103. a second housing; 104. a flexible shaft connecting piece; 104a and a flexible shaft interface.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the present invention can be more readily understood by those skilled in the art. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto.

The present embodiment provides a lightweight decelerator for a robot joint, which is used particularly as a knee joint or a hip joint of a robot. Referring to fig. 1 to 15, the lightweight speed reducer includes a first housing 1, a ring gear 2, a first harmonic steel gear 3a, a second harmonic steel gear 3b, an eccentric shaft 4, an output flange 5, and a sun gear 6. The first housing 1 is hollow and has a ring of first internal teeth 11. The ring gear 2 is made of a high-toughness alloy steel, which is capable of producing a minute amount of elastic deformation; the ring gear 2 has first external teeth 21 and second internal teeth 22, and the ring gear 2 is disposed in the first housing 1 with the first external teeth 21 meshing with the first internal teeth 11. The first harmonic steel gear 3a and the second harmonic steel gear 3b are arranged in parallel, and the second harmonic steel gear 3b is eccentrically arranged with respect to the first harmonic steel gear 3 a. The eccentric shaft 4 is used for driving the first harmonic rigid gear 3a and the second harmonic rigid gear 3b to rotate. The central gear 6 is used for inputting power to drive the eccentric shaft 4 to rotate.

Referring to fig. 1 to 5, the first housing 1 and the gear ring 2 are both hollow and cylindrical with two open ends, and are coaxial, and the first housing 1 is sleeved on the gear ring 2 and is engaged with the first inner teeth 11 and the first outer teeth 21. Wherein the first housing 1 can be fixedly connected to other parts of the robot, for example by means of fasteners, in order to achieve a secure connection of the lightweight gear reducer to the other parts of the robot. The ring gear 2 is a thin-walled elastic ring gear, and the width thereof in the radial direction is less than 10% of the outer diameter thereof, and is capable of generating slight elastic deformation.

As shown in fig. 2 and 8 to 10, the output flange 5 is rotatably provided in the first housing 1, and the output flange 5 is connected to the first harmonic steel gear 3a and the second harmonic steel gear 3 b. Specifically, the output flange 5 is rotatably provided on the eccentric shaft 4. Further, the output flange 5 is located within the first housing 1, and as the first and second harmonic steel gears 3a and 3b rotate, the output flange 5 rotates with respect to the first housing 1.

Further, as shown with reference to fig. 11 to 13, the lightweight speed reducer further includes a motor end flange 7. The motor end flange 7 and the output flange 5 are oppositely arranged and connected with each other, and the first harmonic rigid gear 3a and the second harmonic rigid gear 3b are arranged between the motor end flange 7 and the output flange 5. A motor end flange 7 is rotatably arranged on the eccentric shaft 4 and is located in the first housing 1.

Referring to fig. 4 to 7, the first harmonic rigid gear 3a and the second harmonic rigid gear 3b are two gears having the same structure and the same specification, and are eccentrically provided on the eccentric shaft 4, and both the first harmonic rigid gear 3a and the second harmonic rigid gear 3b have second outer teeth 31 capable of meshing with the second inner teeth 22 of the ring gear 2. Fig. 14 and 15 schematically show the structure of the first harmonic steel gear 3a, and the structure of the second harmonic steel gear 3b is the same as that of the first harmonic steel gear 3 a. Specifically, in the present embodiment, the first harmonic steel gear 3a and the second harmonic steel gear 3b are arranged in parallel in the left-right direction in the ring gear 2, and the first harmonic steel gear 3a is located on the right side and the second harmonic steel gear 3b is located on the left side. The first harmonic rigid gear 3a and the ring gear 2 have a first engagement position, the second harmonic rigid gear 3b and the ring gear 2 have a second engagement position, the first engagement position and the second engagement position are spaced apart from each other in the circumferential direction of the ring gear 2, and further, the first engagement portion and the second engagement portion are respectively located on opposite sides of the ring gear 2, for example, the first engagement position is located on the upper side of the ring gear 2, and the second engagement position is located on the lower side of the ring gear 2.

Referring to fig. 4 and 5, a hollow cavity 40 is opened on the eccentric shaft 4, and the hollow cavity 40 axially penetrates through the eccentric shaft 4 and has two open ends. The hollow cavity 40 is used for wiring (such as a flexible shaft or a signal transmission cable mentioned below) or providing an installation space for other components, so that the whole light speed reducer is compact in structure; meanwhile, the whole light speed reducer is light; therefore, the robot is more suitable for small industrial robots, such as six-axis robots or small mechanical arms. As shown in fig. 4 and 7, the eccentric shaft 4 has a first shaft section 41, a second shaft section 42, a third shaft section 43, a fourth shaft section 44, and an input shaft section 45. Specifically, in the present embodiment, the input shaft section 45, the fourth shaft section 44, the first shaft section 41, the second shaft section 42, and the fourth shaft section 44 are sequentially arranged from right to left. The third shaft section 43, the fourth shaft section 44 and the input shaft section 45 are coaxial, that is, they have a common axial line, which is referred to as a first axial line. The first shaft segment 41 and the second shaft segment 42 are eccentrically disposed with respect to the first axis line, respectively, and both the first shaft segment 41 and the second shaft segment 42 are eccentrically disposed with respect to each other. Specifically, in this embodiment, the axis of the first shaft segment 41 is taken as the second axis, the axis of the second shaft segment 42 is taken as the third axis, the first axis, the second axis and the third axis are parallel to each other, and the second axis and the third axis are respectively located at two opposite sides of the first axis. Furthermore, the first axis, the second axis and the third axis are located in the same plane, the second axis and the third axis are located on two opposite sides of the first axis respectively, the second axis and the first axis have a distance d1, and the third axis and the first axis have a distance d2. Advantageously, the spacing d1 is equal to the spacing d2.

As shown in fig. 6 and 7, the first harmonic rigid gear 3a is disposed on the first shaft section 41, the second harmonic rigid gear 3b is disposed on the second shaft section 42, the output flange 5 is disposed on the third shaft section 43, the motor-end flange 7 is disposed on the fourth shaft section 44, and the sun gear 6 is disposed on the input shaft section 45. Specifically, a bearing 8 is provided between the first harmonic rigid gear 3a and the first shaft section 41 of the eccentric shaft 4, a bearing 8 is provided between the second harmonic rigid gear 3b and the second shaft section 42, a bearing 8 is provided between the output flange 5 and the third shaft section 43, and a bearing 8 is provided between the motor end flange 7 and the fourth shaft section 44. The central gear 6 is tightly sleeved on the input shaft section 45, and the specific assembling process is as follows: the central gear 6 is heated and expanded, then sleeved on the input shaft section 45, and the central gear 6 is tightly sleeved on the input shaft section 45 of the eccentric shaft 4 after cooling. The heating treatment temperature is 80 ℃, the heating treatment time is 3-5 min, and the aperture of the middle hole of the central gear 6 is 30-100 mm.

Referring to fig. 4 and 5, in the present embodiment, the output flange 5 and the motor end flange 7 are both located substantially within the first housing 1, making the structure of the lightweight speed reducer further compact. Specifically, the output flange 5 is connected to the inner wall of the left side portion of the first housing 1 through a bearing 8, and the motor end flange 7 is connected to the inner wall of the right side portion of the first housing 1 through a bearing 8. A sealing ring 9 is also arranged between the output flange 5 and the first housing 1. The lightweight reducer further includes an end cap 51, and the end cap 51 is disposed in a gap between the output flange 5 and the left end portion of the eccentric shaft 4.

The first harmonic steel gear 3a and the second harmonic steel gear 3b are connected to the output flange 5 by a plurality of bolts 101, and output torque. Referring to fig. 8 to 10, a plurality of first bolt holes 52 are formed in the output flange 5; referring to fig. 11 to 13, a plurality of second bolt holes 71 are formed in the motor end flange 7; referring to fig. 14 and 15, the first harmonic steel gear 3a and the second harmonic steel gear 3b have through holes 32, respectively. Bolts 101 are inserted through the first bolt holes 52 of the output flange 5, the through holes 32 of the second harmonic rigid gear 3b and the first harmonic rigid gear 3a, and the second bolt holes 71 of the motor-end flange 7 in this order, thereby connecting the four. Further, the aperture of the through hole 32 is larger than the outer diameter of the bolt 101, thereby allowing the first harmonic steel gear 3a and the second harmonic steel gear 3b to rotate by the eccentric shaft 4. The first bolt holes 52 of the output flange 5, the hole diameters of the second bolt holes 71 of the motor end flange 7, and the outer diameters of the bolts 101 are fitted to each other so as to be closely fitted.

The output flange 5 is fixedly connected with the motor end flange 7, and limits the first harmonic rigid gear 3a and the second harmonic rigid gear 3b to prevent the first harmonic rigid gear and the second harmonic rigid gear from moving along the axial direction of the eccentric shaft 4. Specifically, the output flange 5 and the motor end flange 7 are connected by screws 102. Referring to fig. 8 to 10, the output flange 5 has a plurality of studs 53 extending rightward; referring to fig. 11 to 13, a plurality of second screw holes 72 are formed in the motor end flange 7; referring to fig. 14 and 15, first screw holes 33 are formed in the first harmonic steel gear 3a and the second harmonic steel gear 3b, respectively. The screw 102 is inserted into the stud 53 of the output flange 5 after passing through the second screw hole 72 of the motor end flange 7, the first screw hole 33 of the first harmonic rigid gear 3a and the second screw hole 33 of the second harmonic rigid gear 3b in sequence, so as to connect the four. The first screw holes 33 of the first harmonic rigid gear 3a and the second harmonic rigid gear 3b have a larger diameter than the screws 102, so as to allow the first harmonic rigid gear 3a and the second harmonic rigid gear 3b to rotate under the driving of the eccentric shaft 4.

Specifically, in the present embodiment, the second axis (i.e., the rotation axis of the first harmonic rigid gear 3 a) and the third axis (i.e., the rotation axis of the first harmonic rigid gear 3 a) are respectively located at the upper and lower sides of the first axis, and the distance d1 between the second axis and the first axis is equal to the distance d2 between the third axis and the first axis. Accordingly, the first harmonic steel gear 3a meshes with the upper side of the ring gear 2 at the upper side, and the second harmonic steel gear 3b meshes with the lower side of the ring gear 2 at the lower side, that is, the first mesh and the second mesh are located on the upper and lower sides of the ring gear 2, respectively. The gear ring 2 is initially in a circular ring shape as a whole; when in operation, the upper side part and the lower side part of the gear ring 2 are respectively extruded outwards, and are slightly deformed outwards in the up-down direction, and the left side part and the right side part are deformed inwards, so that the number of the meshed teeth is relatively large, and a larger meshing accommodation angle is provided.

Referring to fig. 5, the light speed reducer further includes a flexible shaft connector 104, and the flexible shaft connector 104 is used for connecting with an output shaft of the motor through a flexible shaft. The flexible shaft connector 104 is engaged with the central gear 6, and the flexible shaft connector 104 is provided with a flexible shaft interface 104a for inserting the end of the flexible shaft. Further, the light speed reducer further comprises a second housing 103, the second housing 103 is fixedly connected with the first housing 1 (for example, through bolt fastening), the input shaft section 45 of the eccentric shaft 4 passes through the second housing 103, a bearing 8 and a sealing ring 9 are arranged between the input shaft section and the second housing 103, and the flexible shaft connecting piece 104 is rotatably arranged on the second housing 103. Referring to fig. 8, the flexible shaft connecting member 104 extends in the left-right direction and is rotatably inserted into the second housing 103, the axis of rotation of the flexible shaft connecting member 104 extends in the left-right direction and is parallel to and does not overlap with the first axis of the input shaft section 45, and the flexible shaft connecting member 104 is located outside the input shaft section 45, as shown in fig. 5. The left end of the flexible shaft connecting piece 104 is provided with external teeth which are meshed with the external teeth of the central gear 6; the flexible shaft interface 104a is positioned at the right end part of the flexible shaft connector 104. Specifically, in this embodiment, the flexible shaft interface 104a is specifically an interface slot, and the interface slot is non-circular (e.g., square), so that the flexible shaft can drive the flexible shaft connector 104 to rotate. The right end of the interface slot is opened for inserting the flexible shaft, and the left end part is in a cone shape with gradually reduced sectional area. The flexible shaft is specifically an elastically deformable flexible cable, the motor can be flexibly installed on other parts (parts with larger space) of the robot, and the flexible cable can adapt to the arrangement of parts and correspondingly bends and deforms, so that the flexible shaft has larger motor installation freedom degree. A bearing 8 and a sealing ring 9 are arranged between the flexible shaft connecting piece 104 and the second shell 103.

The light-duty speed reducer further includes at least two needle bearings 46, and the two needle bearings 46 are disposed on the inner wall of the hollow cavity 40 at left and right intervals. When other components or wiring are provided in the hollow cavity 40 of the eccentric shaft 4, these components or wiring may be fixed to the needle bearing 46 so as to avoid interference with the rotation of the eccentric shaft 4.

In the light speed reducer of the embodiment, the torque flexible shaft output by the motor is transmitted to the flexible shaft connecting piece 104, and then transmitted to the eccentric shaft 4 through the central gear 6, the eccentric shaft 4 rotates, meanwhile, the first harmonic rigid gear 3a and the second harmonic rigid gear 3b are respectively meshed with the gear ring 2 through a plurality of teeth, due to the transmission of small tooth difference, the first harmonic rigid gear 3a and the second harmonic rigid gear 3b rotate in a speed reduction mode under the driving of the eccentric shaft 4 and under the action of the gear ring 2, the torque is transmitted to the output flange 5 through the bolt 101, and the output flange 5 is driven to rotate in a speed reduction mode.

Referring to fig. 2, 4 and 9 to 10, an output end connection port 50 is provided on a left end surface of the output flange 5, and the output end connection port 50 is specifically a blind hole extending left and right. After being assembled into the industrial robot, the light-weight reducer outputs torque to a driving object on the left side; during assembly, the first housing 1 and a support member (e.g., a housing) of a driving object are assembled by a fastening member, and then the right end of the driving object is automatically pressed into the output end connection port 50 of the output flange 5, so that the power input from the motor can be transmitted to the driving object after being decelerated.

The light-duty reduction gear of this embodiment has lightweight, compact structure's characteristics, and convenient assembling, and wherein first casing 1 can fix motionlessly, and transmission part all rotationally sets up in first casing 1, and especially the step of assembling in the industrial robot is comparatively convenient succinct, and the wiring is convenient, effectively reduces the risk that the cable was scraped or was worn and torn. Meanwhile, in the gear meshing process, the flexible deformation of the gear ring 2 is controlled by the meshing of the external teeth of the gear ring 2 and the internal teeth of the first shell 1, and in the controlled deformation state, the included angle between the internal teeth of the elastic gear ring 2 and the eccentric gear can reach 80 degrees, so that the purpose of high torsional rigidity is achieved; multiple speed ratios under the same outer envelope size can be realized by adjusting the tooth number pair of the central gear 6; the light speed reducer has the characteristics of high precision and high torsional rigidity, can be suitable for the working conditions of various speed ratios, and has larger design freedom.

The humanoid robot of this example, the joint of which employs the aforementioned lightweight decelerator. Specifically, the elbow joint or the wrist joint of the humanoid robot adopts the light speed reducer. The humanoid robot further comprises a motor for inputting power to the light speed reducer, the motor is connected with a flexible shaft connecting piece 104 of the light speed reducer through a flexible shaft, and the motor is arranged on the body part of the robot. That is, the motor may be disposed not on the elbow joint or the wrist joint but on the trunk part having a large space, which is advantageous for miniaturization, lightness, and compactness of the arm part of the robot.

As used in this specification and the appended claims, the terms "comprises" and "comprising" are intended to only encompass the explicitly identified steps and elements, which do not constitute an exclusive list, and that a method or apparatus may include other steps or elements. As used herein, the term "and/or" includes any combination of one or more of the associated listed items.

It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. In addition, the descriptions of the upper, lower, left, right, etc. used in the present invention are only relative to the mutual positional relationship of the components of the present invention in the drawings, and reference may be made to fig. 5.

It is further understood that the use of "a plurality" in this disclosure means two or more, and other terms are analogous. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone.

It will be further understood that the terms "first," "second," and the like, are used to describe various information and should not be limited by these terms. These terms are only used to distinguish one type of information from another and do not denote a particular order or importance. Indeed, the terms "first," "second," and the like are fully interchangeable. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope of the present disclosure.

The above embodiments are merely illustrative of the technical ideas and features of the present invention, and are preferred embodiments, which are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention. All equivalent changes or modifications made according to the principles of the present invention should be covered within the protection scope of the present invention.

Claims

1. A light speed reducer comprises a first shell and an output flange, and is characterized in that first inner teeth are arranged on the first shell; the speed reducer further includes:

a first harmonic rigid gear;

the central gear is used for driving the eccentric shaft to rotate;

the flexible shaft connecting piece is connected with an output shaft of the motor through a flexible shaft, is meshed with the central gear and is provided with a flexible shaft interface into which the end part of the flexible shaft can be inserted;

2. The light-duty speed reducer of claim 1, characterized in that, the light-duty speed reducer further includes a second housing, the second housing is fixedly connected with the first housing, the input shaft section passes through the second housing with a bearing disposed therebetween, and the flexible shaft connecting member is rotatably disposed on the second housing.

3. The light speed reducer of claim 2, wherein the flexible shaft connector is inserted into the second housing, a bearing is disposed between the flexible shaft connector and the second housing, and the flexible shaft interface is disposed at an end of the flexible shaft connector and exposed from the second housing.

4. A lightweight reducer according to any one of claims 1 to 3, in which the axis of rotation of the flexible shaft connection is parallel to and does not coincide with the axis of the input shaft section, the flexible shaft connection being located outside the input shaft section.

5. The light-duty speed reducer of claim 1, wherein said input shaft section has a first axis, said first shaft section has a second axis, said third shaft section has a third axis, said first axis, said second axis and said third axis are parallel to each other, said second axis and said third axis are respectively located on upper and lower sides of said first axis, and said first engagement and said second engagement are respectively located on upper and lower sides of said ring gear.

6. The light-duty speed reducer of claim 1, wherein said sun gear is tightly fitted over said input shaft section, and said sun gear is heat treated and fitted over said input shaft section.

7. The light-duty speed reducer of claim 1, wherein said light-duty speed reducer further includes at least two needle bearings, said two needle bearings being spaced apart from each other on an inner wall of said hollow cavity.

8. The light-duty reducer of claim 1, wherein said eccentric shaft further has a third shaft section, said output flange is fitted over said third shaft section with a bearing disposed therebetween; a bearing is arranged between the output flange and the first shell; and/or, the light speed reducer further comprises a motor end flange, the motor end flange and the output flange are oppositely arranged and mutually connected, the first harmonic rigid gear and the second harmonic rigid gear are arranged between the motor end flange and the output flange, the motor end flange is rotatably arranged in the first shell, a bearing is arranged between the first harmonic rigid gear and the output flange, the eccentric shaft is further provided with a fourth shaft section, and the motor end flange is sleeved on the fourth shaft section, and a bearing is arranged between the fourth shaft section and the motor end flange.

9. The lightweight reducer according to claim 8, wherein the first harmonic steel gear and the second harmonic steel gear have through holes, respectively, the output flange and the motor end flange are connected by bolts, and the bolts pass through the through holes of the first harmonic steel gear and the second harmonic steel gear, and the hole diameter of the through holes is larger than the outer diameter of the bolts.

10. A humanoid robot comprising an elbow joint or a wrist joint, characterized in that said elbow joint or wrist joint employs a light-weight decelerator of any one of claims 1 to 9; the humanoid robot further comprises a motor, the motor is connected with a flexible shaft connecting piece of the light speed reducer through a flexible shaft, and the motor is arranged on the trunk part of the robot.