Robot wrist structure and robot

1. A robot wrist structure, comprising:

a case;

a first motor;

a second motor;

a first transmission mechanism;

a second transmission mechanism;

a first driving bevel gear;

a second driving bevel gear;

a driven bevel gear;

a retaining frame; and

an output connecting member,

wherein

the first motor and the second motor are mounted on the case;

the first driving bevel gear, the second driving bevel gear and the driven bevel gear are respectively rotatably mounted in the retaining frame;

an axis of the first driving bevel gear is collinear with an axis of the second driving bevel gear and perpendicularly intersects an axis of the driven bevel gear;

the first driving bevel gear and the second driving bevel gear are both in mesh with the driven bevel gear;

the first motor is connected to the first driving bevel gear by the first transmission mechanism;

the second motor is connected to the second driving bevel gear by the second transmission mechanism; and

the output connecting member is fixedly connected to the driven bevel gear,

wherein

the first transmission mechanism and the second transmission mechanism have the same structure; and

each of the transmission mechanisms comprises a gear transmission mechanism and a belt transmission mechanism,

wherein

the motor, is configured to drive, by the gear transmission mechanism and the belt transmission mechanism in sequence, the driving bevel gear, to rotate,

wherein the gear transmission mechanism comprises a driving gear, a dual gear, a transmission gear, a first planetary gear system, and a second planetary gear system,

wherein

the first planetary gear system comprises a first sun gear, a first planetary gear, a first planetary carrier, and a first ring gear;

the second planetary gear system comprises a second sun gear, a second planetary gear, a second planetary carrier, and a second ring gear;

the belt transmission mechanism comprises an input pulley, an output pulley, and a transmission belt which is disposed around on the input pulley and the output pulley;

the driving gear is connected to an output shaft of the motor;

the dual gear is rotatably mounted in the case;

the driving gear is in mesh with a small gear portion of the dual gear;

a larger gear portion of the dual gear is in mesh with the transmission gear;

the transmission gear is connected to the first sun gear;

the first ring gear and the second ring gear are fixed in the case;

the first planetary carrier and the second sun gear are fixedly connected or integrally formed;

the second planetary carrier is connected to the input pulley; and

the output pulley is connected to the driving bevel gear.

2. The robot wrist structure according to claim 1 ,

wherein

the output connecting member is a U-shaped fork structure; and

the output connecting member comprises a first middle portion; and

a first fork branch and a second fork branch that extend parallelly from both ends of the first middle portion and are oppositely disposed,

wherein

the retaining frame is disposed between the first fork branch and the second fork branch;

the first fork branch is fixedly connected to the driven bevel gear; and

the second fork branch is rotatably connected to the retaining frame.

3. The robot wrist structure according to claim 2 , further comprising:

a rotation shaft,

wherein

the rotation shaft is rotatably mounted on the retaining frame;

an axis of the rotation shaft is collinear with the axis of the driven bevel gear; and

the second fork branch is fixedly connected to the rotation shaft.

4. The robot wrist structure according to claim 3 , wherein the retaining frame is in a shape of a hexahedron;

a first mounting chamber that is inwardly recessed is defined on a left side face of the retaining frame;

a second mounting chamber that is inwardly recessed is defined on a right side face of the retaining frame;

a third mounting chamber that is inwardly recessed is defined on a front side face of the retaining frame; and

a fourth mounting chamber that is inwardly recessed is defined on a rear side face of the retaining frame,

wherein

the first driving bevel gear is disposed in the first mounting chamber;

the second driving bevel gear is disposed in the second mounting chamber;

the driven bevel gear is disposed in the third mounting chamber; and

the rotation shaft is disposed in the fourth mounting chamber.

5. The robot wrist structure according to claim 1 ,

wherein

each of the driving bevel gears, comprises an inner end portion which is proximal to a center of the retaining frame;

an outer end portion which is distal from the center of the retaining frame; and

a gear portion which is disposed between the inner end portion and the outer end portion,

wherein

a diameter of the inner end portion is less than a diameter of the outer end portion;

the inner end portion is mounted on the retaining frame by a first bearing; and

the outer end portion is mounted on the case by a second bearing.

6. The robot wrist structure according to claim 1 ,

wherein

the driven bevel gear comprises an inner end which is proximal to a center of the retaining frame;

an outer end which is distal from the center of the retaining frame; and

a second middle portion which is disposed between the inner end and the outer end,

wherein

gears are defined on the second middle portion;

a diameter of the inner end is less than a diameter of the outer end;

the inner end is mounted on the retaining frame by a third bearing; and

the outer end is mounted on the retaining frame by a fourth bearing.

7. The robot wrist structure according to claim 1 ,

wherein

the case is a fork structure, and comprises a main body, and a first strut and a second strut that extend parallelly from both sides of the main body and are oppositely disposed,

wherein

the main body comprises a first halve and a second halve;

the first halve and the second halve cooperatively defining a chamber for accommodating the first motor, the second motor, the first transmission mechanism and the second transmission mechanism,

wherein

the first strut is connected to the first halve;

the second strut is connected to the second halve;

the first driving bevel gear is rotatably mounted on the first strut; and

the second driving bevel gear is rotatably mounted on the second strut.

8. A robot, comprising: a robot wrist structure; the robot wrist structure comprising:

a case;

a first motor;

a second motor;

a first transmission mechanism;

a second transmission mechanism;

a first driving bevel gear;

a second driving bevel gear;

a driven bevel gear;

a retaining frame; and

an output connecting member,

wherein

the first motor and the second motor are mounted on the case;

the first driving bevel gear, the second driving bevel gear and the driven bevel gear are respectively rotatably mounted in the retaining frame;

an axis of the first driving bevel gear is collinear with an axis of the second driving bevel gear and perpendicularly intersects an axis of the driven bevel gear;

the first driving bevel gear and the second driving bevel gear are both in mesh with the driven bevel gear;

the first motor is connected to the first driving bevel gear by the first transmission mechanism;

the second motor is connected to the second driving bevel gear by the second transmission mechanism; and

the output connecting member is fixedly connected to the driven bevel gear,

wherein

the first transmission mechanism and the second transmission mechanism have the same structure; and

each of the transmission mechanisms comprises a gear transmission mechanism and a belt transmission mechanism,

wherein

the motor, is configured to drive, by the gear transmission mechanism and the belt transmission mechanism in sequence, the driving bevel gear, to rotate,

wherein

the gear transmission mechanism comprises a driving gear, a dual gear, a transmission gear, a first planetary gear system, and a second planetary gear system,

wherein

the first planetary gear system comprises a first sun gear, a first planetary gear, a first planetary carrier, and a first ring gear;

the second planetary gear system comprises a second sun gear, a second planetary gear, a second planetary carrier, and a second ring gear;

the belt transmission mechanism comprises an input pulley, an output pulley, and a transmission belt which is disposed around on the input pulley and the output pulley;

the driving gear is connected to an output shaft of the motor;

the dual gear is rotatably mounted in the case;

the driving gear is in mesh with a small gear portion of the dual gear;

a larger gear portion of the dual gear is in mesh with the transmission gear;

the transmission gear is connected to the first sun gear;

the first ring gear and the second ring gear are fixed in the case;

the first planetary carrier and the second sun gear are fixedly connected or integrally formed;

the second planetary carrier is connected to the input pulley; and

the output pulley is connected to the driving bevel gear.

9. The robot according to claim 8 ,

wherein

the output connecting member is a U-shaped fork structure; and

the output connecting member comprises a first middle portion; and

a first fork branch and a second fork branch that extend parallelly from both ends of the first middle portion and are oppositely disposed,

wherein

the retaining frame is disposed between the first fork branch and the second fork branch;

the first fork branch is fixedly connected to the driven bevel gear; and

the second fork branch is rotatably connected to the retaining frame.

10. The robot according to claim 9 , further comprising:

a rotation shaft;

wherein

the rotation shaft is rotatably mounted on the retaining frame;

an axis of the rotation shaft is collinear with the axis of the driven bevel gear; and

the second fork branch is fixedly connected to the rotation shaft.

11. The robot according to claim 10 ,

wherein

the retaining frame is in a shape of a hexahedron;

a first mounting chamber that is inwardly recessed is defined on a left side face of the retaining frame;

a second mounting chamber that is inwardly recessed is defined on a right side face of the retaining frame;

a third mounting chamber that is inwardly recessed is defined on a front side face of the retaining frame; and

a fourth mounting chamber that is inwardly recessed is defined on a rear side face of the retaining frame,

wherein

the first driving bevel gear is disposed in the first mounting chamber;

the second driving bevel gear is disposed in the second mounting chamber;

the driven bevel gear is disposed in the third mounting chamber; and

the rotation shaft is disposed in the fourth mounting chamber.

12. The robot according to claim 8 ,

wherein

each of the driving bevel gears, comprises an inner end portion which is proximal to a center of the retaining frame;

an outer end portion which is distal from the center of the retaining frame; and

a gear portion which is disposed between the inner end portion and the outer end portion,

wherein

a diameter of the inner end portion is less than a diameter of the outer end portion;

the inner end portion is mounted on the retaining frame by a first bearing; and

the outer end portion is mounted on the case by a second bearing.

13. The robot according to claim 8 ,

wherein

the driven bevel gear comprises an inner end which is proximal to a center of the retaining frame;

an outer end which is distal from the center of the retaining frame; and

a second middle portion which is disposed between the inner end and the outer end,

wherein

gears are defined on the second middle portion;

a diameter of the inner end is less than a diameter of the outer end;

the inner end is mounted on the retaining frame by a third bearing; and

the outer end is mounted on the retaining frame by a fourth bearing.

14. The robot according to claim 8 ,

wherein

the case is a fork structure and comprises a main body, and a first strut and a second strut that extend parallelly from both sides of the main body and are oppositely disposed,

wherein

the main body comprises a first halve and a second halve;

the first halve and the second halve cooperatively defining a chamber for accommodating the first motor, the second motor, the first transmission mechanism and the second transmission mechanism,

wherein

the first strut is connected to the first halve;

the second strut is connected to the second halve;

the first driving bevel gear is rotatably mounted on the first strut; and

the second driving bevel gear is rotatably mounted on the second strut.