Robot arm having weight compensation mechanism

Patent metadata

Field	Value
Publication number	US-2016368151-A1
Application number	US-201614995801-A
Country	US
Kind code	A1
Filing date	Jan 14, 2016
Priority date	Jun 16, 2015
Publication date	Dec 22, 2016
Grant date	—

Abstract

A robot arm having a weight compensation mechanism. In one configuration, the robot arm includes a first link which is pivotably disposed, a first auxiliary link disposed parallel to the first link, a first pulley mounted on the first auxiliary link, a second pulley mounted on the first link, a wire connecting the first pulley to the second pulley, and an elastic member having one side mounted on the first link and the other side connected to the wire to provide an elastic force to compensate for the load of the first link.

First claim

What is claimed is:

1 . A robot arm comprising:
a first link of the robot arm, the first link pivotably disposed; a first auxiliary link of the robot arm disposed parallel to the first link; a first pulley mounted on the first auxiliary link; a second pulley mounted on the first link; a wire connecting the first pulley to the second pulley; and an elastic member having one side mounted on the first link and another side connected to the wire to provide an elastic force to compensate for a load of the first link.

2 . The robot arm according to claim 1 , wherein, the first auxiliary link remains parallel to the first link when the first link is pivoted.

3 . The robot arm according to claim 1 , wherein the wire has:
one end portion thereof fixed to the first pulley, and another end portion thereof configured to pass along a portion of an outer surface of the second pulley and connected to the elastic member.

4 . The robot arm according to claim 1 , wherein a diameter of the first pulley is equal to a diameter of the second pulley.

5 . The robot arm according to claim 1 , wherein a distance between the first pulley and the second pulley varies as the first link is pivoted.

6 . The robot arm according to claim 1 , wherein a center of the second pulley is positioned at an interval apart from a center line passing through a center of the first link and extending along a direction in which the first link longitudinally extends.

7 . The robot arm according to claim 1 , wherein the elastic member is accommodated in an inner space of the first link.

8 . The robot arm according to claim 1 , wherein a center of the first pulley is positioned on a center line extending along a direction in which the first auxiliary link extends and passing through a center of the first auxiliary link.

9 . The robot arm according to claim 1 , further comprising a second auxiliary link connecting the first link to the first auxiliary link.

10 . The robot arm according to claim 9 , wherein the first link and the second auxiliary link are spaced apart from each other by as much as a length of the second auxiliary link and remain parallel to each other even when the first link is pivoted.

11 . The robot arm according to claim 9 , wherein the second auxiliary link is pivotably disposed with respect to respective axes of rotations of the first link and the first auxiliary link.

12 . The robot arm according to claim 1 , wherein the elastic member comprises a plurality of overlapping elastic members.

13 . The robot arm according to claim 12 , further comprising a cap mounted on end portions of the plurality of elastic members to fix the plurality of elastic members.

14 . The robot arm according to claim 13 , wherein
screw threads are formed in an interior of the cap, and each of the plurality of elastic members are fixed by one of the screw threads.

15 . The robot arm according to claim 13 , wherein
a plurality of accommodation units into which the plurality of elastic members are insertable are formed at the cap, and a number of the accommodation units corresponds to a number of the plurality of elastic members.

16 . The robot arm according to claim 15 , wherein
the accommodation units are formed at inner surfaces of the cap, and each of the inner surfaces of the cap forming the accommodation units has a screw thread capable of fixing one of the elastic member.

17 . The robot arm according to claim 13 , further comprising an adjustment device to adjust tension of the elastic member, the adjustment device being disposed at the cap.

18 . The robot arm according to claim 17 , wherein the adjustment device is a shaft having a screw thread formed at an outer circumferential surface thereof and configured to pass through the cap.

19 . The robot arm according to claim 18 , wherein a tension of the elastic member is adjustable by rotating the shaft.

20 . A robot arm comprising:
a first link of the robot arm; a second link of the robot arm configured to remain parallel to the first link when the first link pivots; and a weight compensation mechanism to compensate for a load of the first link by an elastic force, comprising
a first pulley mounted on the first link,
a second pulley having a same diameter as that of the first pulley and mounted on the second link,
a wire connecting the first pulley to the second pulley, and
an elastic member disposed along a direction in which the first link longitudinally extends, configured to provide the elastic force to compensate for the load, and having one side fixed to the first link and another side connected to the wire.

21 . A robot arm comprising:
a first link of the robot arm; a second link of the robot arm pivotably connected to the first link through a joint; a first auxiliary link disposed at an interval apart from the first link; a first pulley disposed at the first auxiliary link; a second pulley disposed at the joint; a third pulley mounted on the second link to move together with the second link; a wire connecting the first pulley, the second pulley, and the third pulley; and an elastic member having one side mounted on the first auxiliary link and another side connected to the wire to provide an elastic force to compensate for the load of the second link.

22 . The robot arm according to claim 21 , wherein the wire is disposed to surround outer portions of the first pulley, the second pulley, and the third pulley.

23 . The robot arm according to claim 21 , wherein the wire has:
one end portion of the wire fixed to the first pulley, and another end portion of the wire connected to the elastic member after passing along the first pulley, the second pulley, and the third pulley.

24 . The robot arm according to claim 21 , wherein a diameter of the first pulley, a diameter of the second pulley, and a diameter of the third pulley are a same size.

25 . The robot arm according to claim 21 , wherein a center of the third pulley is positioned at an interval apart from a center line which extends along a direction in which the second link longitudinally extends and passes through a center of the second link.

26 . The robot arm according to claim 21 , wherein a distance between a center of the first pulley and a center of the third pulley varies as the second link is pivoted with respect to the joint.

27 . The robot arm according to claim 21 , wherein, a distance between a center of the second pulley and a center of the third pulley remains constant when the second link is pivoted with respect to the joint.

28 . The robot arm according to claim 21 , wherein, when the second link rotates clockwise or counterclockwise with respect to the joint, the third pulley rotates clockwise or counterclockwise with respect to the second pulley.

29 . The robot arm according to claim 21 , wherein an accommodation unit in which the elastic member is accommodated is formed at the first auxiliary link.

30 . The robot arm according to claim 21 , further comprising a second auxiliary link connecting the first auxiliary link to the joint.

31 . The robot arm according to claim 21 , wherein the first auxiliary link and the first link are disposed parallel to each other.

32 . The robot arm according

Assignees

• Samsung Electronics Co Ltd
• Univ Korea Ind Univ Coop Found

Inventors

• Han Jeong Heon
• Kim Yong-Jae

Classifications

• Y10S901/15

  Jointed arm · CPC title

• B25J19/0016 Primary

  using springs · CPC title

• Y10S901/48

  Counterbalance · CPC title