CN217414062U

CN217414062U - Flexible robot joint

Info

Publication number: CN217414062U
Application number: CN202220659684.6U
Authority: CN
Inventors: 郭士杰; 卢浩; 贾路宽; 陈力; 杨志强; 邓飞; 关起飞
Original assignee: Fudan University
Current assignee: Fudan University
Priority date: 2022-03-25
Filing date: 2022-03-25
Publication date: 2022-09-13
Anticipated expiration: 2032-03-25

Abstract

The utility model belongs to the technical field of service robots, in particular to a flexible robot joint, which comprises a rotating shaft fixing plate, a joint rotating part, a joint driving mechanism and a driving output mechanism, wherein the joint driving mechanism comprises a hypoid small bevel gear and a hypoid large bevel gear; the rubber elastic coupling is connected with the driving bevel gear and the hypoid large bevel gear through the tooth profiles of the inner ring and the outer ring of the rubber elastic coupling, a transverse rotating shaft is fixedly connected between the two rotating shaft fixing plates, penetrates through the inner ring of the driving bevel gear and has a gap with the inner ring of the driving bevel gear; the drive output mechanism includes driven bevel gear, driven bevel gear and the meshing of drive bevel gear, the vertical pivot of fixedly connected with in the transverse rotating shaft, driven bevel gear fixed connection in vertical pivot, the utility model discloses a two coaxial pivoted gears are connected to the profile of tooth of elasticity rubber shaft coupling, have broken the tradition of rigid connection, carry out the flexible coupling, realize flexible transmission, make this robot joint have high flexible characteristics.

Description

Flexible robot joint

Technical Field

The utility model belongs to the technical field of service robot, concretely relates to flexible robot joint.

Background

The robot joint is mostly series structure at present, and the motor drives the output connecting rod after through slowing down and rotates promptly. Under the working condition that joint size constraint needs large load at the same time, if a nursing robot supports and holds a nursed person, the requirements of structure size and output torque are hardly considered in the traditional series connection result, and the use requirement cannot be met.

In addition, the shape of the mechanical arm composed of the traditional serial robot joints, such as a common cooperative mechanical arm, is convex, and the shape of the human arm is basically smooth, namely the mechanical arm composed of the traditional serial robot joints is difficult to be used in the bionic structure design of the human arm. Meanwhile, the surface with smooth appearance has the potential of covering the surface touch sensor, and great help is provided for comprehensive and safe interaction of human and machine.

In addition, the traditional robot joints are all in rigid transmission, and even if a speed reducer (such as a harmonic speed reducer) in the joints has certain flexibility, the flexibility is very small. At present, a control strategy is adopted to enable a joint to show certain flexibility, the flexibility is called as active flexibility, namely an active compliance control strategy, but the active flexibility of the joint needs larger response time, and when a robot is collided, compliance response cannot be generated in real time. The joints and bones of human body are all connected by soft tissues which can absorb the impact among the bones of human body, and even if the soft tissues are not controlled by the brain, the soft tissue structure also enables the bone mechanism to show good flexibility which is called as passive flexibility. The traditional joint has no flexible transmission unit, and the flexible transmission mechanism among human skeletons cannot be simulated by pure rigid transmission or active flexible control, so that the traditional joint cannot be well adapted to man-machine co-fusion type cooperation.

In summary, at present, no robot joint exists, and the requirements of large load, high flexibility, smooth appearance, low weight and high integration can be met simultaneously.

SUMMERY OF THE UTILITY MODEL

The utility model aims at overcoming the output that exists among the robot joint that exists among the prior art little, do not have passive flexibility, the protruding defect that influences the man-machine contact travelling comfort of arm appearance of constituteing by the joint, provided a high flexibility of heavy load and the smooth robot joint of appearance.

The utility model provides a technical scheme that its technical problem adopted is:

a flexible robotic joint, comprising: the joint driving mechanism comprises a hypoid small bevel gear and a hypoid large bevel gear meshed with the hypoid small bevel gear; the inner ring of the hypoid large bevel gear is connected with a driving bevel gear through a rubber elastic coupling, a transverse rotating shaft is fixedly connected between two rotating shaft fixing plates, penetrates through the inner ring of the driving bevel gear and has a gap with the inner ring of the driving bevel gear; the rotating shaft fixing plate is rotatably connected with the joint rotating member through a first bearing; the driving output mechanism comprises a driven bevel gear, the driven bevel gear is meshed with two driving bevel gears which are arranged oppositely, a longitudinal rotating shaft which is perpendicular to the transverse rotating shaft is fixedly connected to the transverse rotating shaft, the driven bevel gear is fixedly connected to the longitudinal rotating shaft, and the rubber elastic coupling is connected with the driving bevel gear and the hypoid large bevel gear through tooth profiles of an inner ring and an outer ring of the rubber elastic coupling.

Further, still include magnetic encoder, the pivot fixed plate has the bearing installation axle that is used for installing first bearing to the outside convex, bearing installation axle is installed the inner circle of first bearing, the outer end of bearing installation axle is connected with the magnet cover, the downthehole magnet that has of installation magnetic encoder of centre bore of magnet cover, the outside of joint revolving part is fixed with the encoder mounting panel, magnetic encoder's magnetic encoder receiving plate is installed on the encoder mounting panel.

Further, the joint drive mechanism further includes: the device comprises a driving motor, a first encoder connected to a rotating shaft of the driving motor, a driving synchronous belt wheel arranged on an output shaft of the driving motor, a driven synchronous belt wheel connected with the driving synchronous belt wheel through belt transmission, and a speed reducer coaxially connected with the driven synchronous belt wheel, wherein an output shaft of the speed reducer is connected with a hypoid bevel pinion.

Furthermore, the rubber elastic coupling comprises a main rubber ring, an inner connecting boss of which the circumference array is arranged on an inner ring of the main rubber ring, and an outer connecting boss of which the circumference array is arranged on an outer ring of the main rubber ring, the inner ring of the hypoid large bevel gear is provided with an inner connecting groove corresponding to the outer connecting boss, and the outer ring of the drive bevel gear is provided with an outer connecting groove corresponding to the inner connecting boss.

Furthermore, the rubber elastic coupling 5 is in a quincunx shape, and the included angles between the adjacent inner connecting boss 52 and outer connecting boss 53 and the center of the main rubber ring 51 are staggered.

Furthermore, the end part of the longitudinal rotating shaft is fixedly connected with a joint flange connecting piece, the outer side of the joint flange connecting piece is provided with a joint support through a second bearing, and the joint support is fixedly connected with the joint rotating pieces on the two sides.

Further, the outer lane of second bearing is fixed with bearing inner race baffle, be fixed with the encoder fixing base on the bearing inner race baffle, the lower terminal surface fixedly connected with joint transmission flange of the inner circle of second bearing, fixed mounting has joint transmission encoder signal board on the joint transmission flange, fixed mounting has joint transmission encoder signal receiver plate on the encoder fixing base.

Furthermore, the lower end face of the joint transmission flange is fixedly connected with an output connecting piece, the outer side of the output connecting piece is fixedly connected with a sensor adapter plate, and the outer side of the sensor adapter plate is connected with a torque sensor.

Furthermore, the two rotating shaft fixing plates are fixedly connected to a joint transmission seat, a motor mounting seat is fixedly connected to the joint transmission seat, and the driving motor and the speed reducer are mounted in the motor mounting seat.

The utility model discloses a flexible robot joint's beneficial effect is:

1. the robot joint is characterized in that the tooth forms of the inner ring and the outer ring of the elastic rubber coupling made of elastic rubber materials are used for connecting the driving bevel gear and the hypoid large bevel gear, the rubber materials are used for replacing daily screws to fixedly connect the two gears, the rigid connection tradition is broken, the flexible connection is carried out, the flexible transmission is realized, and the robot joint has the characteristic of high flexibility.

2. The robot joint installs a small-volume motor and a high-reduction ratio transmission chain in a cylindrical joint cavity of the robot. The robot joint utilizes a differential structure, can realize the rotation freedom degree of two mutually vertical rotating shafts of one joint, realizes the rotation in two directions, and provides larger output torque so as to bear larger load.

3. The utility model arranges all the components in each cavity of the joint, the whole mechanism has smooth appearance, simple and compact structure and convenient installation and maintenance, so that the robot joint becomes a highly integrated module which can be used independently or matched with other components or the same modules; the utility model discloses can wholly arrange the robot in internally, only carry out electrical connection through a branch of cable and external, the control bus of being convenient for is built, does not influence robot overall structure, the appearance design of being convenient for simultaneously.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Fig. 1 is a schematic perspective view of a robot joint according to an embodiment of the present invention;

fig. 2 is a schematic structural view of a joint cavity according to an embodiment of the present invention;

FIG. 3 is a partial structure view of the joint driving mechanism according to the embodiment of the present invention;

FIG. 4 is a structural diagram of one of the joint driving mechanisms according to the embodiment of the present invention;

fig. 5 is a structural diagram of the rubber elastic coupling according to the embodiment of the present invention;

FIG. 6 is an exploded view of a hypoid bull gear and drive bevel gear attachment in accordance with an embodiment of the present invention;

fig. 7 is a structural view of a bearing fixing plate according to an embodiment of the present invention;

fig. 8 is a view of the mounting structure of the bearing fixing plate and the bearing according to the embodiment of the present invention;

FIG. 9 is a view of the magnetic encoder installation structure of an embodiment of the present invention;

FIG. 10 is a partial block diagram of an embodiment of the invention;

fig. 11 is a structural view of an angular displacement measuring part of the embodiment of the present invention;

fig. 12 is a diagram of a structure of a torque encoder according to an embodiment of the present invention.

In the figure, 1, a rotating shaft fixing plate, 11, a bearing mounting shaft, 2, a joint rotating member, 3, a hypoid small bevel gear, 4, a hypoid large bevel gear, 41, an inner connecting groove, 5, a rubber elastic coupling, 51, a main body rubber ring, 52, an inner connecting boss, 53, an outer connecting boss, 6, a driving bevel gear, 61, an outer connecting groove, 7, a transverse rotating shaft, 8, a first bearing, 9, a driven bevel gear, 10, a longitudinal rotating shaft, 12, a magnetic encoder receiving plate, 13, an encoder mounting plate, 14, a joint flange connecting piece, 15, a second bearing, 16, a joint support, 17, a bearing outer ring baffle, 18, an encoder fixing seat, 19, a joint transmission flange, 20, a joint transmission encoder signal plate, 21, a joint transmission encoder signal receiving plate, 22, an output connecting piece, 23, a sensor adapter plate, 24 and a torque sensor, 25. the motor comprises a driving motor 26, a first encoder 27, a driving synchronous pulley 28, a driven synchronous pulley 29, a speed reducer 30, a joint transmission seat 31, a motor installation seat 32, a driver 33, a battery 34, a control cavity 341, a cable perforation 35 and a magnet sleeve.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic drawings and illustrate the basic structure of the present invention only in a schematic manner, and thus show only the components related to the present invention.

In this embodiment, for convenience of describing the connection manner, the control cavity end is an upper end, and the torque sensor end is a lower end.

Fig. 1-12 show a specific embodiment of a flexible robot joint of the present invention, which can be used for an elbow joint of a humanoid robot, and sequentially comprises a control cavity, a driving cavity and a mechanical transmission cavity from top to bottom.

As shown in fig. 1 and 2, in which the driver and the battery are placed in the control cavity, the control cavity has a cable through hole 341.

The flexible robot joint provided by the embodiment of the utility model comprises two oppositely arranged rotating shaft fixing plates 1, two oppositely arranged joint rotating members 2 which are rotationally connected with the two rotating shaft fixing plates 1, two oppositely arranged joint driving mechanisms and a driving output mechanism which is connected with the joint rotating members 2, wherein the joint driving mechanisms comprise hypoid bevel pinions 3 and hypoid bevel pinions 4 which are meshed with the hypoid bevel pinions 3; an inner ring of the hypoid large bevel gear 4 is connected with a driving bevel gear 6 through a rubber elastic coupling 5, a transverse rotating shaft 7 is fixedly connected between two rotating shaft fixing plates 1, the transverse rotating shaft 7 penetrates through the inner ring of the driving bevel gear 6 and has a gap with the inner ring of the driving bevel gear 6, and the rotating shaft fixing plates 1 are rotatably connected with a joint rotating member 2 through first bearings 8; the driving output mechanism comprises a driven bevel gear 9, the driven bevel gear 9 is meshed with two oppositely arranged driving bevel gears 6, a longitudinal rotating shaft 10 which is perpendicular to the transverse rotating shaft 7 is fixedly connected to the transverse rotating shaft 7, and the driven bevel gear 9 is fixedly connected to the longitudinal rotating shaft 10; the rubber elastic coupling 5 is connected with the driving bevel gear 9 and the hypoid large bevel gear 4 through the tooth profiles of the inner ring and the outer ring of the rubber elastic coupling. Referring to fig. 5 and 6, the rubber elastic coupling 5 includes a main body rubber ring 51, an inner coupling boss 52 circumferentially arrayed at an inner ring of the main body rubber ring 51, and an outer coupling boss 53 circumferentially arrayed at an outer ring of the main body rubber ring 51, the inner ring of the hypoid bevel gear 4 having an inner coupling groove 41 corresponding to the outer coupling boss 53, and the outer ring of the drive bevel gear 6 having an outer coupling groove 61 corresponding to the inner coupling boss 52. The rubber elastic coupling 5 is in a quincunx shape, and the included angles between the centers of the adjacent inner connecting boss 52 and outer connecting boss 53 and the main rubber ring 51 are staggered, so that the force of the hypoid gearwheel 4 can be more uniformly and flexibly transmitted to the driving bevel gear 6. The rubber elastic coupling 5 breaks the tradition of rigid connection, realizes flexible transmission through flexible connection, and is characterized in that the robot joint has high flexibility.

Wherein most spare parts of joint actuating mechanism set up in the drive cavity, refer to fig. 3 and fig. 4, joint actuating mechanism still includes: the device comprises a driving motor 25, a first encoder 26 connected to a rotating shaft of the driving motor 25, a driving synchronous pulley 27 installed on an output shaft of the driving motor 25, a driven synchronous pulley 28 connected with the driving synchronous pulley 27 through belt transmission, and a speed reducer 29 coaxially connected with the driven synchronous pulley 28, wherein an output shaft of the speed reducer 29 is connected with the hypoid bevel pinion 3. The two joint driving mechanisms are oppositely arranged, the two hypoid bevel pinions 3 are respectively meshed with the hypoid bevel pinions 4 on the respective sides to realize differential transmission, and taking the structure in fig. 1 as an example, when the hypoid bevel pinions 3 on the left side and the right side rotate in the same direction and at the same speed, the longitudinal rotating shaft 10 drives the tail ends of the joints to swing up and down around the transverse rotating shaft 7; when the hypoid bevel pinions 3 on the left side and the right side rotate reversely, the longitudinal rotating shaft 10 drives the tail end of the joint to rotate around the axis of the joint; when the hypoid bevel pinions 3 on the left side and the right side rotate in different directions and at different speeds, the tail ends of the joints do comprehensive movement of swinging up and down around the transverse rotating shaft 7 and rotating around the longitudinal rotating shaft 10.

The two rotating shaft fixing plates 1 are fixedly connected to a joint transmission seat 30, a motor mounting seat 31 is fixedly connected to the joint transmission seat 30, and the driving motor 25 and the speed reducer 29 are installed in the motor mounting seat 31.

Referring to fig. 7-9, the embodiment of the present invention further includes a magnetic encoder for measuring the rotation angle of the joint end around the transverse rotating shaft 7, the shaft fixing plate 1 has a bearing mounting shaft 11 protruding to the outside for mounting the first bearing 8, the inner ring of the first bearing 8 is mounted on the bearing mounting shaft 11, the outer end of the bearing mounting shaft 11 is connected with a magnet sleeve 35, a magnet of the magnetic encoder is mounted in the central hole of the magnet sleeve 35, the outer side of the joint rotating member 2 is fixed with an encoder mounting plate 13, and a magnetic encoder receiving plate 12 of the magnetic encoder is mounted on the encoder mounting plate 13.

Referring to fig. 10, a joint flange connecting piece 14 is fixedly connected to an end of the longitudinal rotating shaft 10, a joint bracket 16 is mounted on the outer side of the joint flange connecting piece 14 through a second bearing 15, and the joint bracket 16 is fixedly connected to the joint rotating pieces 2 on both sides.

Referring to fig. 11, the embodiment of the utility model provides a still including being used for measuring the terminal angle displacement encoder around 10 turned angle of vertical pivot of joint, second bearing 15's outer lane is fixed with bearing inner race baffle 17, is fixed with encoder fixing base 18 on the bearing inner race baffle 17, and the lower terminal surface fixedly connected with joint transmission flange 19 of second bearing 15's inner circle, fixed mounting has joint transmission encoder signal board 20 on the joint transmission flange 19, and fixed mounting has joint transmission encoder signal receiving board 21 on the encoder fixing base 18.

Referring to fig. 12, an output connecting piece 22 is fixedly connected to the lower end face of the joint transmission flange 19, a sensor adapter plate 23 is fixedly connected to the outer side of the output connecting piece 22, and a torque sensor 24 is connected to the outer side of the sensor adapter plate 23. The torque sensor 24 is a two-dimensional force sensor, the lower end face of the torque sensor 24 is fixed, the torque sensor 24 rotates coaxially with the joint transmission flange 19 or rotates around the transverse rotating shaft 7 along with the joint rotation body 2, torsional deformation occurs inside the torque sensor 24, and then the output torque of the robot joint in two rotation directions is measured.

A control cavity 34 for placing the driver 32 and the battery 33 is arranged above the motor mounting seat 31, and a cable through hole 341 is formed in the control cavity 34.

The robot joint is characterized in that an elastic rubber coupling made of elastic rubber materials is used for connecting the driving bevel gear 6 and the hypoid large bevel gear 4, the rubber materials are used for replacing daily screws to fixedly connect the two gears, the rigid connection tradition is broken, flexible connection is carried out, flexible transmission is achieved, and the robot joint has the characteristic of high flexibility.

The robot joint has the advantages that the small-size motor and the high-reduction-ratio transmission chain are used for amplifying the torque of the motor and are arranged in a cylindrical joint cavity of the robot. The robot joint utilizes a differential structure, can realize the rotation freedom degree of two mutually vertical rotating shafts of one joint, realizes the rotation in two directions, and provides larger output torque so as to bear larger load.

The utility model arranges all the components in each cavity of the joint, the whole mechanism has smooth appearance, simple and compact structure and convenient installation and maintenance, so that the robot joint becomes a highly integrated module which can be used independently or matched with other components or the same modules; the utility model discloses can wholly arrange the robot in internally, only carry out electrical connection through a branch of cable and external world, the control bus of being convenient for is built, does not influence robot overall structure, the appearance design of being convenient for simultaneously.

It should be understood that the above description of the specific embodiments is only for the purpose of explanation and not for the purpose of limitation. Obvious changes or variations caused by the spirit of the present invention are within the scope of the present invention.

Claims

1. A flexible robotic joint, comprising: the joint driving mechanism comprises a hypoid small bevel gear (3) and a hypoid large bevel gear (4) meshed with the hypoid small bevel gear (3); an inner ring of the hypoid large bevel gear (4) is connected with a driving bevel gear (6) through a rubber elastic coupling (5), a transverse rotating shaft (7) is fixedly connected between the two rotating shaft fixing plates (1), the transverse rotating shaft (7) penetrates through the inner ring of the driving bevel gear (6), and a gap is reserved between the transverse rotating shaft and the inner ring of the driving bevel gear (6); the rotating shaft fixing plate (1) is rotationally connected with the joint rotating member (2) through a first bearing (8); the driving output mechanism comprises a driven bevel gear (9), the driven bevel gear (9) is meshed with two driving bevel gears (6) which are arranged oppositely, a longitudinal rotating shaft (10) which is perpendicular to the transverse rotating shaft (7) is fixedly connected onto the transverse rotating shaft (9), the driven bevel gear (9) is fixedly connected onto the longitudinal rotating shaft (10), and the rubber elastic coupling (5) is connected with the driving bevel gear (6) and the hypoid large bevel gear (4) through tooth profiles of an inner ring and an outer ring of the rubber elastic coupling.

2. A flexible robotic joint according to claim 1, wherein: still include magnetic encoder, pivot fixed plate (1) has bearing installation axle (11) to the convex first bearing (8) of being used for installing of outside, bearing installation axle (11) is installed the inner circle of first bearing (8), the outer end of bearing installation axle (11) is connected with magnet cover (35), the downthehole magnet that has of installation magnetic encoder of magnet cover (35), the outside of joint rotating member (2) is fixed with encoder mounting panel (13), magnetic encoder receiving plate (12) of magnetic encoder are installed on encoder mounting panel (13).

3. A flexible robotic joint according to claim 1, wherein: the joint drive mechanism further includes: the device comprises a driving motor (25), a first encoder (26) connected to a rotating shaft of the driving motor (25), a driving synchronous pulley (27) arranged on an output shaft of the driving motor (25), a driven synchronous pulley (28) connected with the driving synchronous pulley (27) through belt transmission, and a speed reducer (29) coaxially connected with the driven synchronous pulley (28), wherein an output shaft of the speed reducer (29) is connected with a hypoid bevel pinion (3).

4. A flexible robotic joint according to claim 1, wherein: the rubber elastic coupling (5) comprises a main body rubber ring (51), a circumferential array, an inner connecting boss (52) and a circumferential array, wherein the inner connecting boss (52) and the circumferential array are arranged on the inner ring of the main body rubber ring (51), an outer connecting boss (53) is arranged on the outer ring of the main body rubber ring (51), an inner connecting groove (41) corresponding to the outer connecting boss (53) is arranged on the inner ring of the hypoid large bevel gear (4), and an outer connecting groove (61) corresponding to the inner connecting boss (52) is arranged on the outer ring of the driving bevel gear (6).

5. A flexible robotic joint according to claim 4, wherein: the rubber elastic coupling (5) is in a quincunx shape, and the included angles between the connecting boss (52) and the outer connecting boss (53) and the center of the main rubber ring (51) are staggered.

6. A flexible robotic joint according to claim 2, wherein: the end part of the longitudinal rotating shaft (10) is fixedly connected with a joint flange connecting piece (14), the outer side of the joint flange connecting piece (14) is provided with a joint support (16) through a second bearing (15), and the joint support (16) is fixedly connected with the joint rotating pieces (2) on two sides.

7. A flexible robotic joint according to claim 6, wherein: the outer lane of second bearing (15) is fixed with bearing inner race baffle (17), be fixed with encoder fixing base (18) on bearing inner race baffle (17), the lower terminal surface fixedly connected with joint transmission flange (19) of the inner circle of second bearing (15), fixed mounting has joint transmission encoder signal board (20) on joint transmission flange (19), fixed mounting has joint transmission encoder signal receiving board (21) on encoder fixing base (18).

8. A flexible robotic joint according to claim 7, wherein: the lower end face of the joint transmission flange (19) is fixedly connected with an output connecting piece (22), the outer side of the output connecting piece (22) is fixedly connected with a sensor adapter plate (23), and the outer side of the sensor adapter plate (23) is connected with a torque sensor (24).

9. A flexible robotic joint according to claim 3, wherein: two pivot fixed plate (1) fixed connection is on joint driving seat (30), fixedly connected with motor mount pad (31) on joint driving seat (30), install driving motor (25) and reduction gear (29) in motor mount pad (31).