Linear joint and legged robot having the same

Patent metadata

Field	Value
Publication number	US-11485028-B2
Application number	US-201916566908-A
Country	US
Kind code	B2
Filing date	Sep 11, 2019
Priority date	May 16, 2019
Publication date	Nov 1, 2022
Grant date	Nov 1, 2022

Abstract

A linear joint includes a motor assembly includes a rotating shaft for outputting motion; a transmission mechanism including a screw and a nut threadedly connected to the screw, the nut being coaxial with respect to and securely connected to the rotating shaft so as to be rotatable together with the rotating shaft; and a rod connected to a first end of the screw so as to move together with the screw along a lengthwise direction of the screw.

First claim

What is claimed is:

1. A linear joint comprising:
a motor assembly comprising a rotating shaft for outputting motion;
a transmission mechanism comprising a screw and a nut threadedly connected to the screw, the nut being coaxial with respect to and securely connected to the rotating shaft so as to be rotatable together with the rotating shaft; and
a rod connected to a first end of the screw so as to move together with the screw along a lengthwise direction of the screw, wherein the rod comprises an anti-rotation mechanism for preventing the rod from rotating;
a joint housing configured to receive the transmission mechanism therein, wherein the anti-rotation mechanism comprises a groove defined in an outer surface of the rod and extending along a lengthwise direction of the rod, and a ring arranged around the rod, the ring comprises a protrusion that protrudes from an inner surface thereof and is received in the groove;
wherein the rotating shaft comprises a closed end configured to stop movement of the screw when the screw comes into contact with the closed end.

2. The linear joint according, to claim 1 , further comprising a stopper member that is arranged on a second end of the screw which is away from the rod and configured to prevent the screw from disengaging from the nut.

3. The linear joint according to claim 1 , further comprising a linear bearing arranged around the rod and received in the joint housing.

4. The linear joint according to claim 1 , further comprising a first elastic member arranged between the closed end of the rotating shaft and the screw.

5. The linear joint according to claim 1 , wherein the motor assembly comprises a motor having die rotating shaft, a motor housing configured to receive the motor therein, and a roller bearing that is fit in the motor housing and arranged around the rotating shaft, and the rotating shaft is hollow.

6. The linear joint according to claim 5 , further comprising a driver configured to control the motor.

7. The linear joint according to claim 1 further comprising a second elastic member, wherein the first end of the screw is received in the rod, the second elastic member is arranged around the screw and between the nut and the rod.

8. The linear joint according to claim 1 further comprising an encoder arranged adjacent to the closed end of the rotating shaft.

9. The linear joint according to claim 1 further comprising a force sensor and a connecting member, wherein the force sensor is fixed to an end of the rod away from the screw, and configured to detect an axial force acting on the rod, and the connecting member is fixed to an end of the force sensor away from the rod.

10. A legged robot comprising a linear joint, the linear joint comprising:
a motor assembly comprising a rotating shaft for outputting motion;
a transmission mechanism comprising a screw and a nut threadedly connected to the screw, the nut being coaxial with respect to and securely connected to the rotating shaft so as to be rotatable together with the rotating shaft; and
a rod connected to a first end of the screw so as to move together with the screw along a lengthwise direction of the screw;
wherein the rod comprises an anti-rotation mechanism for preventing the rod from rotating, and the rotating shaft comprises a closed end configured to stop movement of the screw when the screw comes into contact with the closed end.

11. A legged robot comprising a lower leg and at least one linear joint connected to the lower leg, the linear joint comprising:
a motor assembly comprising a rotating shaft for outputting motion;
a transmission mechanism comprising a screw and a nut threadedly connected to the screw, the nut being coaxial with respect to and securely connected to the rotating shaft so as to be rotatable together with the rotating shaft; and
a rod connected to a first end of the screw so as to move together with the screw along a lengthwise direction of the screw, which drives the lower leg to move;
wherein the rod comprises an anti-rotation mechanism for preventing the rod from rotating;
wherein the rotating shaft comprises a closed end configured to stop movement of the screw when the screw comes into contact with the closed end.

12. The legged robot according to claim 11 being a four-legged robot and further comprising a body and a linkage bar, wherein the linear joint is connected to the body, and the linear joint, the linkage bar and the lower leg constitute a crank slider mechanism.

13. The legged robot according to claim 11 being a two-legged robot and further comprising two linear joint assemblies and a foot, wherein each linear joint assembly comprises one linear joint and is rotatably connected to the lower leg and the foot, and the foot is rotatably connected to the lower leg.

14. The legged robot according to claim 13 , wherein each linear joint further comprises a bearing and a universal joint fixed to the foot, a first end of each linear joint adjacent to the motor assembly is rotatably connected to the lower leg through the bearing, a second end of each linear joint opposite the first end is rotatably connected to the universal joint.

15. The legged robot according to claim 13 , wherein each linear joint further comprises a bearing, a universal joint fixed to the foot, and a connecting rod, a first end of each linear joint adjacent to the motor assembly is securely connected to the lower leg, a second end of each linear joint opposite the first end is rotatably connected to a top end of the connecting rod through the bearing, and a bottom end of the connecting rod is rotatably connected to the universal joint.

16. The legged robot according to claim 13 , further comprising a control board and a driver electrically connected to the control board, wherein the control board is configured to control the linear joint, and the driver is configured to control the motor assembly.

17. The legged robot according to claim 11 , wherein the linear joint further comprises a force sensor and a connecting member, the force sensor is fixed to an end of the rod away from the screw, and configured to detect an axial force acting on the rod, and the connecting member is fixed to an end of the force sensor away from the rod.

Assignees

• Ubtech Robotics Corp Ltd

Inventors

• Zhang Zhihua
• Zhao Mingguo
• Li Hailei
• Li Kang
• Zhang Weining
• Hei Guangjun
• He Xiaoyu
• Xiong Youjun

Classifications

• B62D57/032 Primary

  with alternately or sequentially lifted supporting base and legs; with alternately or sequentially lifted feet or skid (B62D57/024 takes precedence) · CPC title

• B25J19/0004

  Braking devices (brakes in general F16D) · CPC title

• B25J19/02

  Sensing devices · CPC title

• B25J19/0025

  Means for supplying energy to the end effector · CPC title

• B25J9/123 Primary

  Linear actuators · CPC title