Robot and leg assembly thereof

Patent metadata

Field	Value
Publication number	US-10836032-B2
Application number	US-201916288119-A
Country	US
Kind code	B2
Filing date	Feb 28, 2019
Priority date	Dec 11, 2018
Publication date	Nov 17, 2020
Grant date	Nov 17, 2020

Abstract

A leg assembly of a robot comprising a waist includes a thigh rotatably coupled to the waist, a lower leg rotatably coupled to the thigh, a foot rotatably coupled to the lower leg, a servo fixe to the thigh, a first transmission mechanism configured to transmit motion from the servo to the thigh to drive the thigh to rotate with respect to the waist; a second transmission mechanism configured to transmit motion from the thigh to the lower leg to drive the lower leg to flex when the thigh move upward and extend when the thigh move downward; and a third transmission mechanism configured rotatably connected to the thigh and the foot in such a way that the foot dorsiflexes from an original position when the lower leg is flexing and rotates back toward the original position when the lower leg is extending.

First claim

What is claimed is:

1. A leg assembly of a robot comprising a waist, the leg assembly comprising:
a thigh rotatably coupled to the waist;
a lower leg rotatably coupled to the thigh;
a foot rotatably coupled to the lower leg;
a servo fixed to the thigh;
a first transmission mechanism configured to transmit motion from the servo to the thigh to drive the thigh to rotate with respect to the waist;
a second transmission mechanism configured to transmit motion from the thigh to the lower leg to drive the lower leg to flex when the thigh moves upward and extend when the thigh moves downward; and
a third transmission mechanism configured rotatably connected to the thigh and the foot in such a way that the foot dorsiflexes from an original position when the lower leg is flexing and rotates back toward the original position when the lower leg is extending;
wherein the first transmission mechanism comprises a holder fixed to the waist and a rotating member rotatably connected to the holder about a center axis thereof, the servo is rotatable together with the rotating member and the thigh about the center axis of the rotating member.

2. The leg assembly of claim 1 , wherein the servo comprises an output shaft that is fixed to the rotating member and offset from the center axis of the rotating member.

3. The leg assembly of claim 2 , wherein a ring portion projects radially outwardly from a lateral surface of the rotating member, the holder defines a receiving groove to receive the ring portion so as to prevent an axial movement of the rotating member with respect to the holder.

4. The leg assembly of claim 1 , wherein the second transmission mechanism comprises a fixing frame fixed to the waist, a first linkage bar, a second linkage bar and a third linkage bar, the first linkage bar comprises a top end rotatably connected to the fixing frame and a bottom end, the second linkage bar is rotatably connected to the thigh and comprises a first end rotatably connected to the bottom end of the first linkage bar and a second end, the third linkage bar comprises a lower end rotatably connected to the lower leg and an upper end rotatably connected to the second end of the second linkage bar, a rotation axis around which the thigh rotates with respect to the lower leg is located in front of a rotation axis around which the second linkage bar rotates with respect to the thigh.

5. The leg assembly of claim 4 , wherein the top end of the first linkage bar comprises an axle that comprises a tab at an end thereof, the fixing frame defines a receiving groove to receive the tab therein so as to rotatably connect the top end of the first linkage bar to the fixing frame.

6. The leg assembly of claim 4 , wherein the third transmission mechanism comprises a fourth linkage bar comprising two opposite ends that are rotatably connected to the thigh and the foot, a rotation axis around which the lower leg rotates with respect to the foot is located in front of a rotation axis around which the fourth linkage bar rotates with respect to the foot, and a rotation axis around which the third linkage bar rotates with respect to the lower leg is located in front of a rotation axis around which the fourth linkage bar rotates with respect to the thigh.

7. The leg assembly of claim 6 , wherein the rotation axis around which the thigh rotates with respect to the lower leg is above the rotation axis around which the fourth linkage bar rotates with respect to the thigh.

8. The leg assembly of claim 6 , wherein the foot comprising a mounting member, the lower leg and the fourth linkage bar are rotatably connected to the mounting member.

9. The leg assembly of claim 1 further comprising a stopper limit member fixed to the waist, wherein the thigh comprises a tab defining a sliding groove, the stopper limit member is received in the sliding groove so as to limit the thigh to move in a predetermined range.

10. A robot comprising a waist and a leg assembly, the leg assembly comprising:
a thigh rotatably coupled to the waist;
a lower leg rotatably coupled to the thigh;
a foot rotatably coupled to the lower leg;
a servo fixed to the thigh;
a first transmission mechanism configured to transmit motion from the servo to the thigh to drive the thigh to rotate with respect to the waist;
a second transmission mechanism configured to transmit motion from the thigh to the lower leg to drive the lower leg to flex when the thigh moves upward and extend when the thigh moves downward; and
a third transmission mechanism configured rotatably connected to the thigh and the foot in such a way that the foot dorsiflexes from an original position when the lower leg is flexing and rotates back toward the original position when the lower leg is extending;
wherein the first transmission mechanism comprises a holder fixed to the waist and a rotating member rotatably connected to the holder about a center axis thereof, the servo is rotatable together with the rotating member and the thigh about the center axis of the rotating member.

11. A leg assembly of a robot comprising a waist, the leg assembly comprising:
a thigh rotatably coupled to the waist;
a lower leg rotatably coupled to the thigh;
a foot rotatably coupled to the lower leg;
a servo fixed to the thigh;
a first transmission mechanism configured to transmit motion from the servo to the thigh to drive the thigh to rotate with respect to the waist;
a second transmission mechanism configured to transmit motion from the thigh to the lower leg to drive the lower leg to flex when the thigh moves upward and extend when the thigh moves downward; and
a third transmission mechanism configured rotatably connected to the thigh and the foot in such a way that the foot dorsiflexes from an original position when the lower leg is flexing and rotates back toward the original position when the lower leg is extending;
wherein the second transmission mechanism comprises a fixing frame fixed to the waist, a first linkage bar, a second linkage bar and a third linkage bar, the first linkage bar comprises a top end rotatably connected to the fixing frame and a bottom end, the second linkage bar is rotatably connected to the thigh and comprises a first end rotatably connected to the bottom end of the first linkage bar and a second end, the third linkage bar comprises a lower end rotatably connected to the lower leg and an upper end rotatably connected to the second end of the second linkage bar, a rotation axis around which the thigh rotates with respect to the lower leg is located in front of a rotation axis around which the second linkage bar rotates with respect to the thigh.

12. The leg assembly of claim 11 , wherein the first transmission mechanism comprises a holder fixed to the waist and a rotating member rotatably connected to the holder about a center axis thereof, the servo comprises an output shaft that is fixed to the rotating member and offset from the center axis.

13. The leg assembly of claim 12 , wherein a ring portion projects radially outwardly from a lateral surface of the rotating member, the holder defines a receiving groove to receive the ring portion so as to prevent an axial movement of the rotating member with respect to the holder.

14. The leg assembly of claim 11 , wherein the top end of the first linkage bar comprises an axle that comprises a tab at an end thereof, the fixing frame defines a receiving groove to receive the tab therein so as to rotatably connect the top end of the first linkage bar to the fixing frame.

15. The leg assembly of claim 11 , wherein the third transmission mechanism comprises a fourth lin

Assignees

• Ubtech Robotics Corp

Inventors

• Xiong Youjun
• Liu Defu
• Yang Gao
• Mao Zuyi
• Chen Xinpu

Classifications

• B25J9/106 Primary

  with articulated links · CPC title

• B62D57/032

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

• A63H11/18

  Figure toys which perform a realistic walking motion · CPC title

• B25J9/0006

  Exoskeletons, i.e. resembling a human figure · CPC title

• B25J9/0009

  Constructional details, e.g. manipulator supports, bases · CPC title