CN112720559A

CN112720559A - Collimation drive joint and robot

Info

Publication number: CN112720559A
Application number: CN202011404153.4A
Authority: CN
Inventors: 张明伟; 李海雷; 滕雅婷; 赵明国; 杨国平; 董浩
Original assignee: Ubtech Robotics Corp
Current assignee: Beijing Youbixuan Intelligent Robot Co ltd
Priority date: 2020-12-04
Filing date: 2020-12-04
Publication date: 2021-04-30
Anticipated expiration: 2040-12-04
Also published as: CN112720559B

Abstract

The application belongs to the technical field of robot joints, and particularly relates to a collimation drive joint and a robot. In the collimation drive joint, a motor shaft of a motor assembly is connected with a sun gear of a planetary reducer, a planetary gear is meshed with the sun gear and an inner gear at the same time, and a planetary shaft is connected with the planetary gear and a planetary carrier. When the planetary gear set works, the motor shaft drives the sun gear to rotate at a high speed, the sun gear drives the planetary gear to rotate, the planetary gear is in meshing transmission with the inner gear, and then the planetary shaft drives the planetary carrier to rotate at a low speed and output torque. A motor end sensor is arranged to detect the rotating position of the motor shaft, so that the position of the motor shaft is corrected. The collimating drive joint adopts the planetary reducer, has large reduction ratio and high transmission efficiency, ensures that the collimating drive joint has small back drive moment, and is suitable for the situation of robot moment control. The collimating drive joint has the characteristics of strong universality, high integration level, high power density, high transmission efficiency, small rotational inertia, good back drive performance, impact resistance and low cost.

Description

Collimation drive joint and robot

Technical Field

The application belongs to the technical field of robot joints, and particularly relates to a collimation drive joint and a robot.

Background

With the development of the robot control technology, the control requirements for the driver also change, and the driver is required to realize torque control from position control to force-position hybrid control and impedance control. The force control joint also appears in different forms based on different principles, namely a quasi-direct-drive, series-connection elastic driver and a rigid driver based on a force sensor. The quasi-direct drive has higher torque density compared with the direct drive, can realize higher force control bandwidth compared with a series elastic driver, can reach higher speed, greatly reduces the structural complexity and cost compared with a rigid driver based on a force sensor, and realizes the robustness of coping with impact on the basis of the characteristic of low resistance of a body of the quasi-direct drive. How to obtain a quasi-direct drive joint with good torque control performance becomes an urgent problem to be solved in the industry.

Disclosure of Invention

An object of the embodiment of the application is to provide a collimation drive joint and a robot, so as to solve the technical problem that the prior art is difficult to obtain a collimation drive joint with good torque control performance.

The embodiment of the application provides a collimation drives joint, includes:

a housing;

the motor assembly comprises a stator arranged in the shell, a rotor coaxially arranged with the stator and a motor shaft coaxially fixed on the rotor;

the planetary reducer comprises a sun gear coaxially fixed on the motor shaft, a planetary gear meshed with the sun gear, an inner gear fixed on the shell and meshed with the planetary gear, a planetary carrier coaxially arranged with the sun gear and rotatably mounted on the shell, and a planetary shaft used for connecting the planetary gear and the planetary carrier; and

a motor end sensor for detecting a rotational position of the motor shaft.

Optionally, the housing has a cylindrical portion, the internal gear is at least partially mounted within the cylindrical portion, and the planet carrier is at least partially mounted within the internal gear.

Optionally, the planet carrier comprises a first annular part and a second annular part which are coaxially arranged at an interval, and a connecting arm connected between the first annular part and the second annular part; the two ends of the planet shaft are respectively connected to the first annular part and the second annular part, and the planet wheel is rotatably mounted on the planet shaft and positioned between the first annular part and the second annular part;

the first end of the inner gear has a first annular wall; the first annular portion is supported by the first annular wall via a first bearing, and the second annular portion is supported by the opening of the cylindrical portion via a second bearing.

Optionally, the outer race of the first bearing is floatingly disposed relative to the first annular wall;

the first annular part is provided with a mounting groove for mounting a first bearing, the first annular part is provided with a first annular end cover, and two ends of an inner ring of the first bearing are respectively abutted to the end face of the mounting groove and the first annular end cover.

Optionally, an oil seal for blocking a gap between the inner hole of the first annular end cover and the motor shaft is arranged on the motor shaft.

Optionally, the second end of the internal gear has a second annular wall, the opening edge of the cylindrical part is provided with an inner flange, and two ends of the outer ring of the second bearing respectively abut against an end face of the second annular wall and an end face of the inner flange;

the second annular part is provided with an outer flange, the second annular part is provided with a second annular end cover, and two ends of the inner ring of the second bearing are respectively abutted to the end face of the outer flange and the second annular end cover.

Optionally, the planet wheels are supported on the planet shaft by a third bearing.

Optionally, the planetary reducer is disposed in the motor assembly, the stator is sleeved outside the cylindrical portion, and the rotor is sleeved outside the stator; the motor shaft has a bracket on which the rotor is mounted.

Optionally, the housing includes a fixing frame and a tail cover mounted on the fixing frame, and the cylindrical portion is formed on the fixing frame; the motor assembly and the planetary reducer are arranged in the fixed frame; the tail cover is provided with a through hole which is arranged opposite to the cylindrical part and through which the motor shaft passes.

Optionally, the sun gear includes a connecting shaft and a gear portion disposed on the connecting shaft, a first end of the connecting shaft is coaxially fixed to the motor shaft, a second end of the connecting shaft is supported by the planet carrier through a fourth bearing, and the motor shaft is supported by the housing through a fifth bearing.

Optionally, the motor shaft has a stepped hole, the first end of the connecting shaft is inserted into the stepped hole, and one end surface of the gear part abuts against one end surface of the motor shaft; the step face of shoulder hole is equipped with solid fixed ring, gu fixed ring with be equipped with the screw between the connecting axle, the screw passes gu fixed ring and spiro union in the connecting axle, gu fixed ring's both ends are supported respectively to be located the head of screw with the step face of shoulder hole.

Optionally, the connecting shaft and the motor shaft are connected by a key or a profile.

Optionally, the motor end sensor includes a sensed member disposed at one end of the motor shaft, and a sensing member cooperating with the sensed member to detect a rotational position of the motor shaft.

Optionally, the motor end sensor is one of a photoelectric encoder, a magnetic encoder, a capacitive encoder, a rotary transformer, and a potentiometer.

The embodiment of the application provides a robot, including foretell accurate directly drive joint.

One or more technical solutions provided in the embodiments of the present application have at least one of the following technical effects: in the collimation drive joint, a motor shaft of a motor assembly is connected with a sun gear of a planetary reducer, a planetary gear is meshed with the sun gear and an inner gear at the same time, and a planetary shaft is connected with the planetary gear and a planetary carrier. When the planetary gear set works, the motor shaft drives the sun gear to rotate at a high speed, the sun gear drives the planetary gear to rotate, the planetary gear is in meshing transmission with the inner gear, and then the planetary shaft drives the planetary carrier to rotate at a low speed and output torque. A motor end sensor is arranged to detect the rotating position of the motor shaft, so that the position of the motor shaft is corrected. The collimating drive joint adopts the planetary reducer, has large reduction ratio and high transmission efficiency, ensures that the collimating drive joint has small back drive moment, and is suitable for the situation of robot moment control. The collimating drive joint has the characteristics of strong universality, high integration level, high power density, high transmission efficiency, small rotational inertia, good back drive performance, impact resistance and low cost.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

FIG. 1 is a perspective assembly view of a collimating driver joint provided by embodiments of the present application;

FIG. 2 is another perspective assembly view of the alignment drive joint of FIG. 1;

FIG. 3 is a cross-sectional view of the alignment drive joint of FIG. 1;

FIG. 4 is an exploded perspective view of the alignment drive joint of FIG. 1;

FIG. 5 is an exploded perspective view of the motor assembly and motor end sensor of the collimating driver joint of FIG. 4;

FIG. 6 is an exploded perspective view of the planetary gear set in the collimating drive joint of FIG. 4;

FIG. 7 is an exploded perspective view of the housing of the alignment drive joint of FIG. 4.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

In the description of the embodiments of the present application, it is to be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like refer to orientations and positional relationships illustrated in the drawings, which are used for convenience in describing the embodiments of the present application and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the embodiments of the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless specifically limited otherwise.

In the embodiments of the present application, unless otherwise specifically stated or limited, the terms "mounted," "connected," and "fixed" are to be construed broadly, e.g., as meaning fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the embodiments of the present application can be understood by those of ordinary skill in the art according to specific situations.

Referring to fig. 1, 2 and 4, an alignment drive joint according to an embodiment of the present invention includes a housing 100, a motor assembly 200, a planetary reducer 300 and a motor end sensor 400. Referring to fig. 5, the motor assembly 200 includes a stator 210 disposed in the housing 100, a rotor 220 disposed coaxially with the stator 210, and a motor shaft 230 coaxially fixed to the rotor 220. Referring to fig. 6, the planetary reducer 300 includes a sun gear 310 coaxially fixed to the motor shaft 230, a planetary gear 320 engaged with the sun gear 310, an inner gear 330 fixed to the housing 100 and engaged with the planetary gear 320, a planetary carrier 340 coaxially disposed with the sun gear 310 and rotatably mounted to the housing 100, and a planetary shaft 350 for connecting the planetary gear 320 and the planetary carrier 340. Referring to fig. 1 and 2, the motor end sensor 400 is used to detect the rotational position of the motor shaft 230.

Compared with the prior art, the collimating driving joint provided by the application has the advantages that the motor shaft 230 of the motor assembly 200 is connected to the sun gear 310 of the planetary reducer 300, the planet gear 320 is meshed with the sun gear 310 and the inner gear 330 at the same time, and the planet shaft 350 is connected with the planet gear 320 and the planet carrier 340. In operation, the motor shaft 230 drives the sun gear 310 to rotate at a high speed, the sun gear 310 drives the planet gears 320 to rotate, the planet gears 320 are in meshed transmission with the inner gear 330, and then the planet shaft 350 drives the planet carrier 340 to rotate at a low speed and output torque. The motor end sensor 400 is provided to detect the rotational position of the motor shaft 230, thereby achieving correction of the position of the motor shaft 230. The collimating drive joint adopts the planetary reducer 300, has large reduction ratio and high transmission efficiency, ensures that the collimating drive joint has small back drive moment, and is suitable for the situation of robot moment control. The collimating drive joint has the characteristics of strong universality, high integration level, high power density, high transmission efficiency, small rotational inertia, good back drive performance, impact resistance and low cost.

The collimation drive joint adopts the planetary reducer 300, has high transmission efficiency, can obtain better torque control performance, and has small back drive torque. The planet carrier 340 in the planetary reducer 300 is connected with the actuator to drive the actuator to work. Wherein the implement may be an arm, leg structure, or other structure of the robot. When external impact force is transmitted to the collimation drive joint by the executing piece, the back drive moment of the collimation drive joint is small, and the internal mechanism of the joint can be protected to reduce the possibility of damage of the internal mechanism. When the executing piece is subjected to the resistance torque of a human body or other objects, the reverse driving torque of the collimation driving joint is small, so that the collimation driving joint can work continuously, and the joint which is low in transmission efficiency does not stop working due to large reverse driving torque as the conventional joint. The characteristics are suitable for the torque control situation of the robot, the corresponding output torque can be obtained by inputting the preset current to the motor assembly, and a torque sensor is not needed to detect the output torque for correction.

When the motor assembly 200 is provided, an external rotor motor, a split motor, a permanent magnet synchronous motor, a direct current brushless motor or other forms can be selected. When the stator 210 is energized, a rotating magnetic field is generated, and under the action of the rotating magnetic field, the rotor 220 will rotate, thereby driving the motor shaft 230 to rotate.

When the planetary reducer 300 is provided, the sun gear 310, the planet gears 320, and the inner gear 330 may be provided as spur gears, helical gears, or other types of gears. The number of the stages of the planetary reducer 300 can be set to one or more stages, and the number of the single-stage planetary wheels 320 can be set to one or more so as to meet different transmission ratio requirements. Illustratively, three planet gears 320 are provided and are evenly distributed along the circumference of the planet carrier 340, and the sun gear 310 is installed on the central axis of the planet carrier 340 and is meshed with all the planet gears 320 at the same time.

In another embodiment of the present application, referring to fig. 3 and 7, the housing 100 has a cylindrical portion 111, the internal gear 330 is at least partially installed in the cylindrical portion 111, and the planet carrier 340 is at least partially installed in the internal gear 330. This facilitates the assembly of the inner gear 330 to the housing 100 and makes full use of the axial space to make the structure compact. For example, the annular portion 331 is provided on the outer peripheral surface of the internal gear 330, a part of the internal gear 330 is inserted into the cylindrical portion 111 of the housing 100, the annular portion 331 is brought into contact with one end of the cylindrical portion 111, the cylindrical portion 111 and the annular portion 331 are fixed together by a fastener, and the internal gear 330 is fixed to the cylindrical portion 111. The internal gear 330 may be attached to the cylindrical portion 111 by a close fit or a snap fit.

In another embodiment of the present application, referring to fig. 3 and 6, the planet carrier 340 includes a first annular portion 341 and a second annular portion 342 coaxially spaced apart, and a connecting arm 343 connected between the first annular portion 341 and the second annular portion 342; the planet shaft 350 has two ends respectively connected to the first annular portion 341 and the second annular portion 342, and the planet 320 is rotatably mounted on the planet shaft 350 and located between the first annular portion 341 and the second annular portion 342. This facilitates assembly of the sun gear 310, the planet gears 320, the planet carrier 340, and the planet shaft 350 such that the planet gears 320 mesh with both the inner gear 330 and the sun gear 310. Illustratively, three connecting arms 343 are arranged between the first annular portion 341 and the second annular portion 342, and two adjacent connecting arms 343 are arranged at intervals to form mounting positions for mounting the planet wheels 320. The planet shaft 350 can be fixed on the first annular portion 341 or the second annular portion 342 through tight fit, and the planet wheel 320 is sleeved on the planet shaft 350 and axially limited by the first annular portion 341 and the second annular portion 342.

Further, referring to fig. 3 and 6, the first end of the inner gear 330 has a first annular wall 332. The first annular portion 341 is supported by the first annular wall 332 via a first bearing 361, that is, an inner ring of the first bearing 361 is fixed to the outside of the first annular portion 341, and an outer ring is fixed to the inside of the first annular wall 332. The second annular portion 342 is supported by the opening of the cylindrical portion 111 via a second bearing 362, that is, the second bearing 362 has an inner ring fixed outside the second annular portion 342 and an outer ring fixed inside the cylindrical portion 111. The first bearing 361 and the second bearing 362 support the planet carrier 340, so that the planet carrier 340 is stably rotatably mounted on the casing 100, and the bending moment, the axial force and the radial force borne by the joint load end can be improved. The first bearing 361 may be a deep groove ball bearing, and can bear radial load and axial load. The second bearing 362 may be a cross roller bearing, which is a bearing in which an inner ring is divided and an outer ring rotates, and has high rigidity, and a bearing gap is adjustable, so that high-precision rotational motion can be obtained.

In another embodiment of the present application, referring to fig. 3 and 6, the outer ring of the first bearing 361 is disposed in a floating manner relative to the first annular wall 332, i.e., there is no axial limit on both sides of the outer ring of the first bearing 361. The first annular portion 341 has a mounting groove 3411 for mounting the first bearing 361, the first annular portion 341 is provided with a first annular end cover 363, and two ends of the inner ring of the first bearing 361 respectively abut against the end surface of the mounting groove 3411 and the first annular end cover 363, so that the axial limit of the inner ring of the first bearing 361 is realized. This supports the first annular portion 341 on the first annular wall 332 of the internal gear 330. Wherein the first annular end cap 363 may be secured to the first annular portion 341 with a fastener.

In another embodiment of the present application, please refer to fig. 3 and 5, an oil seal 240 for blocking a gap between the inner hole of the first annular end cover 363 and the motor shaft 230 is disposed on the motor shaft 230. Lubricating oil is arranged in the planetary reducer 300, and the oil seal 240 is arranged to prevent the lubricating oil from leaking out of the gap, so that the planetary reducer 300 can operate in an oil-filled environment, and the reliability is improved. For example, the oil seal 240 may be an annular baffle facing the gap between the inner hole of the first annular end cap 363 and the motor shaft 230, and inclined with respect to the axis of the motor shaft 230 for good blocking effect.

In another embodiment of the present application, please refer to fig. 3 and fig. 6, a second end of the internal gear 330 has a second annular wall 333, an inner flange 1111 is disposed at an opening edge of the cylindrical portion 111, and two ends of an outer ring of the second bearing 362 respectively abut against an end surface of the second annular wall 333 and an end surface of the inner flange 1111, so as to achieve axial position limitation of the outer ring of the second bearing 362. The second annular portion 342 has an outer flange 3421, the second annular portion 342 has a second annular end cap 364, and two ends of the inner ring of the second bearing 362 respectively abut against the end face of the outer flange 3421 and the second annular end cap 364, so as to limit the inner ring of the second bearing 362 in the axial direction. This allows the second annular portion 342 to be supported in the cylindrical portion 111, and the overall structure is compact. Wherein the second annular end cap 364 may be secured to the second annular portion 342 by fasteners.

In another embodiment of the present application, referring to fig. 3 and 6, the planet 320 is supported on the planet shaft 350 through the third bearing 321, so as to reduce the resistance in the transmission process. The third bearing 321 may be a needle bearing, and occupies a small space.

In another embodiment of the present application, referring to fig. 2 to 4, the planetary reducer 300 is disposed in the motor assembly 200, the stator 210 is sleeved outside the cylindrical portion 111, and the rotor 220 is sleeved outside the stator 210. Therefore, the axial size of the quasi-direct-drive joint can be reduced, and the overall structure is compact. The stator 210 may be fixed outside the cylindrical portion 111 by gluing or other means. Referring to fig. 5, the motor shaft 230 has a bracket 232, and the rotor 220 is mounted on the bracket 232. Illustratively, the bracket 232 includes a plurality of support arms 2321 circumferentially disposed outside the motor shaft body and a connection ring 2322 connected to the distal end of each support arm 2321, and the rotor 220 may be mounted on the connection ring 2322, for example, by gluing.

In another embodiment of the present application, referring to fig. 1, 3 and 7, the housing 100 includes a fixing frame 110 and a tail cap 120 mounted on the fixing frame 110, and the cylindrical portion 111 is formed on the fixing frame 110. The motor assembly 200 and the planetary reducer 300 are disposed in the fixing frame 110. The tail cover 120 has a through hole 123 provided opposite to the cylindrical portion 111 and through which the motor shaft 230 passes. The fixing frame 110 and the tail cover 120 are easy to be formed and assembled separately, and after the motor assembly 200 and the planetary reducer 300 are assembled in the fixing frame 110, the collimating driver joint becomes an independent module. The fixing frame 110 and the tail cover 120 can be connected through a fastener, and the assembly is easy. The fixing frame 110 and the tail cap 120 can be respectively provided with

air holes

112 and 121, which is convenient for air flow and heat discharge during joint operation.

In another embodiment of the present application, referring to fig. 3 and 6, the sun gear 310 includes a connecting shaft 311 and a gear portion 312 disposed on the connecting shaft 311, a first end of the connecting shaft 311 is coaxially fixed to the motor shaft 230, a second end of the connecting shaft 311 is supported on the planet carrier 340 through a fourth bearing 314, and the motor shaft 230 is supported on the housing 100 through a fifth bearing 235. The second end of the connecting shaft 311 is inserted into the carrier 340 and supported by the fourth bearing 314, which makes the planetary reducer 300 compact. The motor shaft 230 is coaxially fixed with the sun gear 310, and the motor shaft 230 is supported by the sun gear 310 and the fourth bearing 314 and is coaxial with the stator 210, so that the stable rotation of the motor shaft 230 and the sun gear 310 is facilitated, the resistance in the rotation is reduced, and the reliability is improved. Illustratively, the second end of the connecting shaft 311 is supported within the second annular portion 342 by a fourth bearing 314. Illustratively, the inner race of fifth bearing 235 is axially positioned by locating surface 233 of motor shaft 230 with locating ring 234 mounted on motor shaft 230, and the outer race of fifth bearing 235 is positioned by locating flange 122 of tail cap 120.

In another embodiment of the present application, referring to fig. 3 and 5, the motor shaft 230 has a stepped hole 231, and the first end of the connecting shaft 311 is inserted into the stepped hole 231. One end surface of the gear portion 312 abuts against one end surface of the motor shaft 230. The stepped surface 231a of the stepped hole 231 is provided with a fixing ring 371, a screw 372 is arranged between the fixing ring 371 and the connecting shaft 311, the screw 372 penetrates through the fixing ring 371 and is screwed with the connecting shaft 311, and two ends of the fixing ring 371 abut against the head 372a of the screw 372 and the stepped surface 231a of the stepped hole 231 respectively. This arrangement allows for coaxial assembly of the motor shaft 230 and the sun gear 310. The stepped hole 231 includes a large hole 231b and a small hole 231c which are communicated with each other, the inner diameter of the large hole 231b is larger than that of the small hole 231c, the stepped surface 231a is located between the large hole 231b and the small hole 231c, and the small hole 231c is arranged close to the sun gear 310. The outer diameter of the head 372a of the screw 372 is larger than the inner diameter of the fixing ring 371, the outer diameter of the fixing ring 371 is larger than the inner diameter of the small hole 231c, and the outer diameter of the fixing ring 371 is smaller than the inner diameter of the large hole 231 b. During assembly, the connecting shaft 311 of the sun gear 310 is inserted into the small hole 231c, the fixing ring 371 is inserted into the large hole 231b, the screw 372 penetrates through the fixing ring 371 and is screwed to one end of the connecting shaft 311, the end face of the gear part 312 abuts against one end of the motor shaft 230, and the fixing ring 371 is clamped between the head 372a of the screw 372 and the step face 231a, so that the axial locking between the motor shaft 230 and the sun gear 310 is realized. Further, the connecting shaft 311 is connected with the motor shaft 230 by a key 313 or a profile connection, so that torque transmission is realized.

In another embodiment of the present application, referring to fig. 3 and 5, the motor end sensor 400 includes a sensed member 401 disposed at one end of the motor shaft 230, and a sensing member 402 cooperating with the sensed member 401 to detect the rotational position of the motor shaft 230. The sensed part 401 and the sensing part 402 cooperate to detect the rotation position of the motor shaft 230, and the motor driver is combined to realize the position correction of the motor shaft 230. The motor drive may be integrated on the alignment drive joint or disposed external to the alignment drive joint. Further, motor shaft 230 is provided with an annular mounting seat 4011 by tight fit or other methods, annular sensed part 401 can be fixed on mounting seat 4011 by bonding or other methods, and mounting seat 4011 is provided with a through hole for motor shaft 230 to pass through, so that sensed part 401 can be assembled on motor shaft 230 conveniently. In addition, referring to fig. 4, a protective cover 130 is further disposed on the housing 100 for protecting the motor end sensor 400.

In another embodiment of the present application, referring to fig. 1 and fig. 3, the motor end sensor 400 is one of a photoelectric encoder, a magnetic encoder, a capacitive encoder, a rotary transformer, and a potentiometer. These methods are all capable of detecting the rotation position of the motor shaft 230, and belong to the prior art.

Illustratively, when a magnetic encoder is used, a magnet is used as the sensed member 401, and a magnetic encoding chip is used as the sensing member 402. When the motor shaft 230 rotates, the magnet rotates synchronously with the motor shaft 230, the rotation of the magnet causes the change of the magnetic field intensity, and after the magnetic coding chip detects the change of the magnetic field intensity, the rotation motion of the magnet is converted into pulses to be output so as to reflect the current rotation angle.

Illustratively, when a photoelectric encoder is used, a photoelectric code disc is used as the sensed member 401, and a photoelectric detection device is used as the sensing member 402. The photoelectric code disc is formed by equally opening a plurality of rectangular holes on a circular plate with a certain diameter. The photoelectric detection device comprises a light-emitting diode and a photosensitive tube which are respectively arranged at two sides of the photoelectric code disc. When the motor shaft 230 rotates, the photoelectric code disc and the motor shaft 230 rotate synchronously, the light emitting diode emits light signals, the photosensitive tube receives the light signals passing through the rectangular hole of the photoelectric code disc, the photoelectric detection device outputs a plurality of pulse signals, and the current rotation angle can be reflected by calculating the number of pulses output by the photoelectric encoder.

In another embodiment of the present application, please refer to fig. 1 to 3, which provide a robot including the quasi-direct drive joint. Since the robot adopts all technical solutions of all the embodiments, all the beneficial effects brought by the technical solutions of the embodiments are also achieved, and are not described in detail herein.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. An alignment drive joint, comprising:

a housing;

a motor end sensor for detecting a rotational position of the motor shaft.

2. The alignment drive joint of claim 1 wherein the housing has a cylindrical portion, the inner gear is at least partially mounted within the cylindrical portion, and the planet carrier is at least partially mounted within the inner gear.

3. The alignment drive joint of claim 2 wherein said planet carrier includes first and second coaxially spaced annular portions and a connecting arm connected between said first and second annular portions; the two ends of the planet shaft are respectively connected to the first annular part and the second annular part, and the planet wheel is rotatably mounted on the planet shaft and positioned between the first annular part and the second annular part;

4. The alignment drive joint of claim 3, wherein the outer race of the first bearing is floatingly disposed relative to the first annular wall;

5. The alignment drive joint of claim 4 wherein said motor shaft has an oil seal disposed thereon for blocking a gap between said inner bore of said first annular end cap and said motor shaft.

6. The alignment drive joint as set forth in claim 3, wherein the second end of the internal gear has a second annular wall, the opening edge of the cylindrical portion has an inner flange, and both ends of the outer ring of the second bearing respectively abut against an end surface of the second annular wall and an end surface of the inner flange;

7. The alignment drive joint of claim 3, wherein the planet is supported on the planet shaft by a third bearing.

8. The alignment drive joint as set forth in claim 2, wherein said planetary reducer is disposed within said motor assembly, said stator is disposed outside said cylindrical portion, and said rotor is disposed outside said stator; the motor shaft has a bracket on which the rotor is mounted.

9. The alignment drive joint of claim 2, wherein the housing includes a mount and a tail cap mounted to the mount, the barrel being formed on the mount; the motor assembly and the planetary reducer are arranged in the fixed frame; the tail cover is provided with a through hole which is arranged opposite to the cylindrical part and through which the motor shaft passes.

10. The alignment drive joint of any one of claims 1 to 9, wherein the sun gear includes a connecting shaft and a gear portion provided on the connecting shaft, a first end of the connecting shaft is coaxially fixed to the motor shaft, a second end of the connecting shaft is supported on the carrier by a fourth bearing, and the motor shaft is supported on the housing by a fifth bearing.

11. The alignment drive joint of claim 10, wherein the motor shaft has a stepped bore, the first end of the connecting shaft is inserted into the stepped bore, and an end face of the gear portion abuts against an end face of the motor shaft; the step face of shoulder hole is equipped with solid fixed ring, gu fixed ring with be equipped with the screw between the connecting axle, the screw passes gu fixed ring and spiro union in the connecting axle, gu fixed ring's both ends are supported respectively to be located the head of screw with the step face of shoulder hole.

12. The alignment drive joint of claim 11, wherein the shaft is keyed or molded to the motor shaft.

13. The alignment drive joint of any of claims 1 to 9, wherein said motor end sensor includes a sensed member disposed at one end of said motor shaft and a sensing member cooperating with said sensed member to detect a rotational position of said motor shaft.

14. The alignment drive joint of any of claims 1 to 9, wherein the motor end sensor is one of a photoelectric encoder, a magnetic encoder, a capacitive encoder, a rotary transformer, and a potentiometer.

15. A robot comprising the alignment drive joint of any of claims 1 to 14.